better, keeping to this sort of wing loading will guarantee a brisk takeoff and make the landings a bit less fraught.
If you do these numbers for a Wot4 you'll see it makes less than an ideal conversion, it can be done, but you'll need more cells and it will be something of a hot ship to land. Could always build a wing with more span I suppose. Would certainly improve the appearance. Sorry, my prejudice is showing.
One other rule worth knowing if you're designing your own plane from scratch is that the powertrain - motor, gearbox, prop, battery and speed controller - should make up half the flying weight. Gulp.
The actual conversion is the easy bit just take out the glow motor, tank and throttle servo and mount the electric motor in it's place. Chuck away the engine mount, it's weight you don't need. 1/8 ply is thick enough for mounting electric motors.. For the Taube conversion, I carved away nearly all the 1/4 ply firewall and mounted the motor by gluing 1/8 ply plates onto what used to be the 1/4 balsa motor cowling. Plenty strong enough - no vibration to worry about is there?
The battery box can made up of 1/8 hard balsa. Stop worrying about what the battery will do in a crash, there's no point. If you crash a glow plane you'll wipe out everything ahead of the wing, so what's different with an electric? It might be politic to put the speed controller out of the way of the battery, but you ain't going to stop 28 oz of battery from ploughing it's way to the front, so don't even try. Just make sure it's not going to crush anything expensive on it's way. All you need to do is make the battery box strong enough to stop the battery getting loose in aerobatics and landings and make it open enough that cooling air can get past the battery. The really good news is that you can chuck out all that lead you put in the nose to get the thing to balance, just move the battery forward a bit. Have you noticed how scale biplanes and vintage models always seem to come out tail heavy? Not any more!
Make sure that cooling air can get over the motor, the speed controller and the battery. This is usually fairly easy to do, but don't forget to have an exit for the air somewhere near the back of the fuselage. It will need to be quite a big hole, around an inch square.
Move the receiver back as far as you can and put a 250mAh battery in instead of the standard 500mAh. The idea of moving the receiver back is to get it as far away as possible from the biggest source of interference, the motor, which you suppressed according to the instructions, didn't you? A 250mAh battery is more than enough for a days flying and will save 2 oz. Just think how much time you normally spend fiddling with a glow engine to get it started and running right with the radio switched on. All that will be a thing of the past. Switch on, push the throttle forward and fly!

Talking of the throttle, if you're the kind of pilot who treats the throttle as an on-off switch, don't even think about getting into electrics. An electric aeroplane is a bit like a slightly over weight 40 glow model with a 2 oz tank. You're going to get 3-4 mins at full throttle, 7-9 mins if you throttle back as much as possible, even turn the motor off if you want to come down a bit - don't worry, it'll start again! Full power is only used for takeoffs, touch and gos and the entry to loops and stall turns. On the downward bit of aeros the motor will unload anyway and save you some current, turning it off will save even more. Climbing uses most power, which is why it is always better to over power an electric - you spend less time going up, so you get longer flights. It sounds illogical, but I know it's true, so trust me. All right, an example. F5B models use so much power (1500-2000Watts) that they can't run the motor for more than 10 seconds without a melt down. In that 10 seconds they climb vertically at over 100 mph to eye-straining altitude. Typical flight times are in the 15-30 minute range! All my landings are done motor off with maybe a trickie of power if it looks like getting a bit low on the approach. No, planes don't crash if the motor stops - they become civilised aeroplanes called gliders. Sorry, get off hobby horse!
In my opinion there's only one make of battery worth buying - Sanyo. 1700SCRs are now pretty cheap, I've seen seven cell packs for £30 at the shows, mainly because the new RC2000s have arrived which are the same size and weight but have 18% more capacity and a lower internal resistance. There are even rumours of some new nickel metal hydride cells suitable for electric flight that have twice the capacity of RC2000s. Wow! With these, I'll have the equivalent of a 40 with a 6 oz tank! Bet they'll cost an arm and a leg though.
Speed controllers are no problem, there's plenty out there that will handle 14 cells and up to 30A, and they're getting cheaper all the time. For instance, F2A Supplies do the Kontronic Easy 5000 for only £37.50.
Safety rules with electrics are the opposite to glow. If the propeller isn't going round, then it's probably going to. Keep your hands well away at all times, there might be a battery in the model and it might be switched on just waiting for a glitch to spin the prop or the throttle to be nudged open accidentally. A 14 cell model has the same power as a Black and Decker drill, in fact a fair bit more when stalled. You can just imagine the damage an APC on a Black and Decker can do to your fingers. Please don't find out the hard way. Get into a safe switch on routine.
Tx on, throttle closed, Rx on, then connect the battery with hands well clear of the prop.
Reverse this on landing. DO NOT switch off your Tx to retrieve your model from the patch. If you pick up interference the motor might start and you'll be chasing the thing all over the field, or worse, trying to explain why little continued