Diana 34. I have 3. Still a good buy.
$250 for a 20+ FPE rifle, (and a scope), that is going to drop coons/possums at 50+ yds, is going to be difficult. You might want to consider watching air gun classifieds for a used gun. Be patient, and you may come up with a decent deal from a respected member.
Benjamin 392Williams peep
did you look at the hatsan 95 or 85 sniper?
there is a Rws 350 magnum in the classified section now that is in your price range.
What gun would you buy if you had 250 bucks lying around???