Personally , I think every gun is going to pattern different- Ex- My Dad and I both shoot the Rem 11-87 SPS,
He shoots a Comp-n-Choke .665 and gets incredible results- But you put that same choke in my gun and the results are dramaticlly different,,, dont know why but they are.
Any of the aftermarket Superfull Turkey Chokes will work, but finding the exact one that shoots the way you are pleased with is the key-
In other words, I've got probably 5-6 chokes sitting in the gun cabinet that I shot a dozen times or so and put up because it wasnt what I was looking for.
The choke that came with the gun WILL shoot a good pattern but could probably be improved with any of the aftermarket chokes.
As far as Turkey loads- Shoot a bunch of them and find what does best for your Gun.
Hevishot thou is the up and coming loads- THEY ARE D-E-A-D-L-Y-