Re: EMG or SD
Tonally, they are two completely different animals. You'll find people saying one sounds much better than the other, but a lot of it is just preference. Personally, I've never tried the EMGs so I can't make a fair comparison. The LWMs will overdrive your amp more - it's almost impossible to play clean.
If I understood your last question correctly, yes. You need space for two 9V to run the Live Wires.