All a matter of preference and what produces the pattern you like. I'd pattern them all.
usually full and xtra full are used for turkeys
Personally I enjoy modified for the rest of my upland bird hunting, and my skeet/trap score goes nicely with that statement.
Buckshot should be good with modified, but personally never fired it.
Just as a warning you will notice a little more kick with tighter choke tubes.
I'm sure other's will tell you what they do.
My Rem. Wingmaster has a modified barrel on it and I fire slugs through it as well without a problem, and awesome 100 yard accuracy.
