Hi,
I've registered with pigeonwatch specifically to respond to your question!
I used to farm, and for a number of years was training border collies almost semi-professionally for either trials or farmwork (depending on the individual dog's abilities or limitations). I also ran them in trials up to national level. So I know a bit about the breed.
The first thing I'd say is that you can train up a border collie up to do pretty much anything, so yes, you could make a passable gundog from one. However, there are some massive caveats.
1) They're super sensitive and very easy to ruin. Your average gundog breed will forgive and forget even the grossest transgressions on the part of the handler. But border collies never get over any loss of trust.
2) They won't do what they don't want to do and they're too intelligent to bash through pain. Consequently I have my doubts about how a collie would face thick cover. In point of fact, a lot of modern bred-for-trials dogs won't even face determined livestck with much conviction.
3) The dog would be under-employed. I always inquire of people who ask about border collies as pets 'Would you keep a Porsche 911 to pull the caravan?'because it's a valid comparison. Yes, the Porsche could probably do the job, but there are far better towing vehicles, and it would be a crime to waste such a car's potential by hitching a caravan to it.
If you want my advice for what it's worth, it would be to get a dog that's bred for the job. There are lots of breeds out there, and they'll all make better gundogs than a border collie would. Just as importantly in your case, they'll almost certsinly make better house dogs too.
When it comes to collies, what a lot of people forget is that while you can take the dog off the hill, you can't take the hill out of the dog. A dog that, for generations, has been selectively bred to run 50 to 80 miles a day on an open hillside and respond to complex commands delivered from half a mile or more away never really comes to terms with the energy and stimulation restrictions of average pet life. Chasing a frisbee (or even retrieving a pheasant) is not a substitute for bossing 200 sheep on a Perthshire hillside, or diving in to sort off twins from singles in a fank. And that's why if you go to any rehoming website there are always masses of border collies of up for adoption. In the house, they're square pegs in round holes and the result is disharmony all round. It's extremely saddening to see.
Get a spaniel. Fun, bulletproof to train, relaxed at home when there's no work, but absolutly loves what it does when there is. What more could you want?