I would shoot a slower 1 ounce shell for the first shot but 1180 seems to be whats available.
I haven't reloaded in years.
I also use 7&1/2 for singles and Caps @ 1145FPS. Keeps it simple.
To be honest I have used every possible combination of shells.
Same with chokes.
I don't think it makes much difference for me.
The gun I broke the most 100's in doubles with had .031 in bottom n .046 in top.
Gun I broke second most had .022/.036.
Couple others in there that were choked similar.
Been shooting a tubed gun for a few years and at times trying to act like a sporting shooter and use weak chokes. Weak chokes don't work for me. Nothing less than .030 for second shot for darn sure.
Loads, Leo turned me into a 1oz first shot shooter 30 yrs ago. Been messing with 7/8oz loads for a year off and on and thinking i like them. I like 8.5's but 9's if not available. Second shot usually 1145fps rated 7.5 or 8.
I messed with a lot of shell and choke combos through the years. What is most important with both is what you can consistently break targets with and that which you have peace of mind in using.