I don't know the stock number, but I seem to like what many other forum members like: the 7rnd mag, welded base plate, round convex metal follower. These have been great in a pistol of mine that is very picky about mags. Perhaps someone else will know the stock number off hand.
You will find guys using both types. I find the 7 round mags to be more reliable. They also have the advantage that slide-lock occurs between targets - less chance of losing track of where you were than when it occurs during the engagement of one target (i.e. one on the target, reload, one more on the same target). This only applies, of course, if the targets are to be engaged with two rounds. I use 9 round magazines when I shoot 38 Super for the same reasons.
I use 8-round mags for CDP competition. I have several different brands, all adjusted for my guns and reliable on feeding and slide stop operation. But I carry 7s because I still consider them even more reliable
I have tried the 7+1 and 9+1 gimmick so as to come to slidelock after finishing a two-hit target and it does help you on the pickup and reengagement. If you don't miss. If the CoF doesn't have some three shot targets or a Popper. Big if, these days. I ALWAYS include at least one non-doubletap stage in a match I set up.
The big consideration is, you MUST use the SAME magazine capacity throughout. Carrying both 7 and 8 round magazines along for purpose of scheduling reloads is not allowed.