If recoil is really a problem for you look for an 1100 or 11-87 in 20 ga with a rifled barrel, cantilever barrel if you want it scoped. Then get a good after market recoil pad, like a simms or something simular. Adding some sort of recoil reduction device inside the stock wouldn't hurt either.

And remember, with recoil weight is your friend.

You could also look into a stock that absorbs recoil like they use for skeet and trap. I would suggest checking out some skeet forums if you are interested in that.

Also keep in mind some 20 ga shells kick about as hard as some 12 ga shells, really depends on how they are loaded.

The H&Rs are heavy and nice on recoil, but I bet a gas operated gun would feel even better. I own an H&R Ultra in 12 ga and it still thumps me pretty good.

You also might want to consider going with open sights over a scope. If you are really that prone to head injuries getting whacked with a scope by accident will not be a good thing. If you do get a scope look for a good one with generous eye releif, at least 4 inches would be my advice. In your situation I would really look at getting a gun with good open sights and spending the money you would have spent on optics for a better gun or recoil absorbption (is that a word? doesn't look right).

Just my thoughts anyway.

Paul