Have a 686 Sporting 30" that I primarily do some skeet with. Wanted some new chokes for it and was debating if I should go with the U0 or U1 as they're both marked skeet? Thanks!

Try one of each. Both are range appropriate for skeet targets...

I know several shooters including my son that use the U0 quite often on sporting targets inside 25 yards (skeet range) with excellent success.

UO/UO for skeet.

Actually, I shoot a U1 on the bottom and a U0 on the top barrel. I shoot the bottom barrel first, except for Stations 6 and 7 singles, and both houses on Station 8.