What do you think about a Clark 2774337 Electric Drive Forklift Motor From a Model ECS30 36-48VDC going into a Chevy s10 5 speed?
I just saw one of these online for less than 500 dollars, used. Sounds like a pretty good price!
About your question: I asked Steve Clunn from Green Shed Conversions whether or not he thought this motor would work for your Chevy S-10 conversion. He said yes, this motor will work, but you'll have to weld the coupler right to that shaft, and you'll have to make an adapter plate for it to connect to the transmission.
On the voltage rating: Steve said people have run these at much higher voltages.