You've caught me at a 3-way intersection to give an opinion... With my opinion on this one, it will not be anywhere near as cut & dried as it would be under different circumstances. First off, I am a huge Remington 700 fan. I have quite a few of them. They are my favorite bolt-action rifles hands-down.
However, you have got me at an intersection because I am a big 700 fan, a big .308 Win fan, and a HUGE 7mm RemMag fan.
So, logically, I would have to say, that you should buy a Rem 700 in 7mm RemMag, and some reloading equipment. Then you will be happy all the way around. Then later on, buy a .308 Win for target shooting.
That to me, seems the only way to fix your problems.