I have a PICAXE 28X. Its a package made for learning microcontrollers as it has alot of extra functions already built into it. It comes with a disc with all of the commands and tutorials of how to use them. It also has tutorials for interfacing circuits and there is one that shows you how to use a solenoid so I though I would have a go. It recommends using the IRF530, which is can handle up to 14 amps.
By F/V do you mean frequency/voltage? Yes it has PWM out and is what it recommends to use.
PIC programming is easy, working out the logic for the program is the difficult yet fun part.
Providing I get it working, who is going to offer the doner car? As my car won't be running for a long time.