If you are thinking ultramag I would look at the 300 instead of the 7mm. Same velocity as the 7mm. It just seems like too much powder to drive down that small of a barrel to me.

Federal has expanded its lineup of 7MM-WSM ammo and they have some nice bullet options now for various situations.The WSM does slightly outperform the Remmington magnum ifthat is what you are looking for.
If you are hunting Texas whitetails another 280 would be a good pick also.