Just general ideas, you could post him on craigslist but list him with a required application for people to fill out (with husbandry questions and whatnot) and email to you to apply.

I also never think "free to good home" is a good idea for the reasons you listed. A truly good home would not mind at all spending $20 or $30 rehoming fee for their new pet, and proves they at least are willing to spend money on their pet (vet bills, equipment, etc).