You won't find motors much lower in price than what you see already. If you scour the want ads in OSE, RumRunner RC etc, you can find some nice used stuff.

The cheapest 2215's I've seen were on OSE, they don't sell Lehners.

You could go with an inexpensive large chinese outrunner and power it on 10 or 12S.

Les expensive HV controllers?? Maybe wait for the HIFEI 240Amp HV marine unit. Don't know when its coming out but, its on HIFEI's web site.

There is a Turnigy Monster 2000, 200 amp HV esc at Hobby City. I own one but, can't run it until the ice thaws. I have water proofed it and added water coooling tubes to the heatsinks.

It's very beefy, should be good.

Thats all I can say fo now.