The thing is that you pretty much need the fancy controller OR two controllers to use the dual speed feature. You could use only the low speed or only the high speed, however, the high speed is pretty high current draw, and the inrush current during startup would be pretty severe. If that's what you wanted to do, I'd use a controller for low speed, and have a switch to turn a relay on for the high speed that is manual. So, you'd use the same diagram as above for the relays but connect the second trigger wire to your switch. You have to use the 70A relays regardless. No normal controller without relays or switch can handle the current draw.
The low speed is probably plenty. I'll bet you can still get these things wicked cheap at a salvage yard. Hell here's a listing on Ebay for $35
http://www.ebay.com/itm/1999-CONTOU...its=Model:Contour&hash=item58ab8c0de2&vxp=mtr
