Thanks Paul. I too am happy that I have a bigger garage for my toys. Not too long ago I had a smaller place to work in and it was a pita.
Higher C rated battery won't give you that much more umphh from the get go, until update/upgrade your controller. The higher c rated batteries will have less voltage drop under load. This will give you more speed in a stock setup. Voltage equals speed and Amperage equals to torque.
I've used laptop cells, A123's cells and lipo cells. Lipo is the cheapest way to go. Just get decent cells to start off with and manage them well. Don't go below 15-20% capacity and charge up to 4.15V per cell for a increase in life cycles. 30-40C cells are my preference. In cold weather I charge up to 4-4.1V per cell, which is about 80% capacity.
This raptor bike pulls a peak of 90A and can do a 80A continuous under 115% throttle. There are not many premade battery packs out there that support my bike. But there are plenty premade battery packs if you have a bike that will consume 1000-1500W continuous. If you have a good soldering skills, you can make a pretty good homemade pack. Get a quality fuse holder and good plugs for your battery build. I use a combination of EC5, 6.5mm bullets and 45A anderson connectors. Make sure you have a precharge setup to charge up the caps in the controller and avoid the plug in sparks.