Well, I've started collecting parts for the project.
Over the weekend I picked up a 300W 24V scooter motor for $30 shipped off ebay. I'm really hoping this is large enough to spin the blade and cut grass. I think it might be a little on the small side, but the price was right and I couldn't pass it up. If its too small I'm sure I can find another use for a 300W permanent magnet motor.
Last night I picked up the mower for the project too. Its my uncle's 20 year old Honda push mower. He recently replaced it with a reel mower since the engine was making odd sounds. Its a bit on the heavy side I think, but it should work. One downside is it doesn't have a side discharge. Its really only setup for bagging which I have no interest in using a bagger. So, I'll have to make something up for side discharge.
Pictures to come.
I'm still looking for suggestions too. I'd still like to keep the build price under $150 but exceeding that a little is okay too.