RE: 7 mm ultra mag, good gun?
My cousin has a model 700 in 7mm Remington Ultra Mag. He loves it - I know some other people that love it as well. I haven't heard of the barrel problem, but it is a very fast round so you probably have to watch that.
The thing I'd be concerned about is that the 7mm RUM is considered by many to be a flop in terms of how popular its been. Translation = if you don't reload, it may be very difficult to find ammo for it 5 or 10 years from now. That's what I've been hearing anyways.
If you don't reload, I'd recommend the plain Jane 7mm Remington Mag - you lose some velocity, but it's still a very good round and you'll alwasy be able to find ammo for it.