Been a while since I did mine, but IIRC any 10" sub should fit... However everything I could find at the time would need an enclosure built behind it. Without that, at best it'll sound rubbish, at worst kill the woofer.

What I did in the end was buy an Alpine PWE-S8 "under seat" subwoofer and stuff that in the space behind the driver's seat. Already had a shelf built in there for the main amp, so that wasn't too big a deal.

Dear god no. 

They are going to a good cause 

Thnks again mate,.

Yeah it is paint friendly, just remove any that goes on the paint very quickly before it cures.