If I were going to use a 7mm I think that I would have to go with a 7mmWSM , but if you want real speed from it then a 7-300wby or 7mmRUM. The 7mm Dakota makes for a great round due to its short fat case being able to seat long bullets out real far and still work in a bolt action repeater , BUT , I ststed a few reasons that the Dakots just isin't realy a viable option to me I have a 300Dakota and I think that there are better alternitives out there.
The 7mm Remington magnum is no slouch by any means and should be given consideration
I don't know about the 7mmSTW have never delt with one but that is one long case and may cause problems feeding from the mag with bullets seated out far.
The question is , what do you expect this gun to do for you ??