Q: Recording two people in two diffrent locations

It's actually quite difficult to do it the way professional broadcasters used to before the advent of high-quality digital lines. It involves recording both ends at the same time and then editing the resulting two recordings together to produce the result - very time-consuming and I doubt you would want to attempt it. (The process is called a 'simulrec' and I recorded one end of one of these for the BBC with the far end being in new York - in the end New York lost their tape so we had to use my recording complete with transatlantic cable quality).

Frankly the best way is to use Skype or something similar and record at your end - the incoming quality is normally pretty reasonable. I doubt you could do this on an iPad, though I don't actually know. On a Mac you could use Audio Hijack Pro to record from Skype. Obviously this is something you would want to experiment with before doing it for real.