The hunting version of the Irish setter is know known as a Red setter. If you buy an I.S. you'll likely be disappointed as a hunter. I'd also be concerned about the very limited gene pool that's available for Red Setters, maybe someday they'll be a better bet but if it's a pointing dog you want, I'd stick w/ one of the more traditional choices.
I'm one of those odd people who actually prefer a flushing dog for my upland work. I could pretend it's because I'm such a fine wingshooter that I need the challenge that a pointed bird fails to provide because this is the internet and nobody can prove otherwise.:>) The truth is somewhat harder to explain, but I really do enjoy the way a good flushing dog uses his nose on moving pheasants and grouse. I also demand a very high standard of retrieving that very few pointing dogs can provide. It absolutely ruins my day to leave a bird in the field because I couldn't find it. And the fact is that I've actually spent a lot of effort improving my wingshooting over the last few years so that I can allow my flushers to range out more and for pheasants especially, it's a much more rewarding shot.
For all those reasons, I favor one of the retrievers over the setter. Which one depends on how much waterfowling you do.
I've had several fine Labs and two exceptional Golden Retrievers (from field trial lines of course.) It's definitely a lot easier to find a good Lab than a good Golden, but I have to say if you find a good one, it will take your breath away watching them hunt the uplands.
Both Goldens I've owned had noses that rivaled any Springer and far surpassed my Labradors. Neither of them were as efficient markers as my top Labs but they both handled better on blinds. I don't mean the Goldens couldn't mark singles and doubles, they just had to be handled in Master/Finished hunt tests on triple retrieves too often.
Overall, for a hard core waterfowler, get a Lab-there's no comparison. If you also hunt pheasant or grouse, and you can afford to wait for the right litter and pay a couple hundred $ more, a top quality Golden is an awesome and highly under-rated hunting dog.
This opinion is guaranteed to be 100% correct or your money back.