I've always used Winchester and CCI 209s for trap and skeet because that's what our gun club usually carried and what I bought depended on what was in stock at the time...the primers I happened to have on hand right now are CCI's so that's what I used.
These blackpowder shells just have Goex powder, a 1/2" prelubed fiber cushion wad, and shot...no shot cup.

Don't know about the PSI level but I have to believe its moderate or less...these are actually an eyelash less than a basic 3 dram (82grns) & 1oz shot small game field load