That's awesome to hear, badfishracing!! Could you get someone to do a video of your race? I would love to see it!!
If you use 220vDC batteries, you would need at least 300v mosfets, but that's not much headroom. It might be better to just do IGBTs. If you want soliton1 current, I would use 3 600v 600amp IGBTs. I'll be putting together a kit for that soon. I have some boards, and you could follow the instructables here if you were feeling really really really DIY:
200kW AC Motor Controller for Electric Car: 18 Steps (with Pictures)
(instead of the AC board, just use the DC board)