RE: 20 gauge too big?
some 20's will hurt alot worse than a 12 with managed recoil loads. i had an H and R single shot 20 that was plain painfull to shoot.
a good auto 12 (SBE, SBE2, remington) will eat lighter loads and not hurt a bit.
a bit more versatility in the 12's too.
just stuff to think about.
moose