With everyone else chiming in, I thought I would give my .02 worth.
First and foremost, shoot and then shoot some more. I say that with all the other things out there, shooting is practice and you can't get enough of that. The best shotgunners out there shoot a lot!!!
I grew up in rural NC and have been hunting since I was 14...a long time ago!!! I shot single shots and pumps, then moved to doubles and eventually an auto. Almost everyday after school, the first thing I did when I got home was to pick up my gun and go outside in the woods and fields. Every Saturday, my friend and I took his beagles out and did the run and gun on rabbits. We were young and never wanted to wait for the rabbit to make the full circle. I hunted everything that was in season and the rest of the year, I hunted varmints and predators.
Doing all that shooting and hunting, I surprised my good friend when years later, he took me to his local trap shooting club. I told him that I use to hunt and shoot a lot but it had been 15 years since I shot much. That first time on the 16yd line, I broke 24 of 25. I did that regularly. Every once in a while, I would run the clays. I was using my newly purchased 870 police with a 26" vent rib barrel. Everyone else had their 'Trap' guns, Perazzi's, Benelli's, Browning's, etc. and they just nodded their heads and smiled. I guess what I am trying to say, go ahead and get what you want, but get into shooting a lot. You might find that it really doesn't matter that much which kind of grip you shoot. The only way to get any good with any gun is to practice. You might as well bust some clays for that instant gratification. There are many ways to enjoy that to. When I was growing up, there was only Skeet and Trap. Now there is Sporting Clays and 5 Stand. These simulate hunting more in my book than either of the other two, but, I still enjoy shooting Trap.
One other thing when shooting clays...remember, you are really only competing against yourself. Don't fall into the trap of getting competitive with others. Your concentration will suffer along with your score. You can have more fun by getting better and beating them eventually!!!
Then after shooting alot, you will figure out what kind of grip you like and are good with.
Cohibra45