Bruce, let me put a couple .02 into this conversation. My history, well I started loading shotshells before I got into rifle, then pistol in 1969. Those shells were for ducks, the plastic wads/shells were brand new back then, the Remington "power piston wad" had only been around for 5-6 years.
When I got started, I found an old f**t in a basement under a liquor store selling shotshell components along with loaders and most importantly tested data. He set me up with Hercules herco, a charge bar for the 600 jr. mec he sold me, for 1 1/4 ounce loads. It had a powder hole that dispensed 26.5 grains of herco. Then he sold me 100 empty AA shells, and a 250 count of rem sp-12 wads! Yup, the same ones you're asking about. WW-209 primers, a bag of #6 chilled shot and I was ready to load shells.
Those shells put the shot out at 1300 fps, with a pattern out of my rem 870 full choke that was nearly 85% at 40 yds! The important part of the sp-12 wad is the construction. It has the slits only half way back to the bottom of the cup. This holds the back half of the shot for a few milliseconds longer than the front half, resulting in center heavy patterns. Then, it has a rib on the inside that further strengthens the wad fingers.
Later,(about 5-6 years), I switched to WW-540,(HS-6), at 33.0 grains. Those loads were about the same velocity and had nearly the same patterns,(same hull).
For your wants, I would go with the 800X also. This data is from the Lyman 4th edition shotshell handbook, "the bible".
800X, 25.5 grains, one (1) sp12, win 209 primer, 1291 fps, 9,300 LUP.
For universal clays, there's very little, nothing for the sp12, but using the rem. R12H, 26.0 univ. clays, win 209, 1222 fps, at 8,600 LUP.
The above suggested Unique powder has a load using the sp12.
Unique, 24.0, CCI 209, one (1) sp12, 1285 fps, at 9,600 LUP.
All of these loads would be very effective for small game. Of course we can't use them on waterfowl anymore!
Personally, I would go with magnum hard shot to improve the patterns and increase the penetration. These loads are where you will save money reloading shotshells. The premium heavy field loads, are quite expensive.
If you have anymore questions, ask away, I've probably been there, done that.