Re: Tapered bases
If you need taper bases than I'll assume that you anticipate shooting at quite a long distance. With that in mind, I would much prefer a 300WSM, 300WinMag, or any one of the other 300 mags for shooting elk at those ranges, but thats not to suggest that a .308win can't work.
To answer your question: I would suggest using a set of Burris Signature rings with the exchangeable inserts. This way you could use just enough taper to get the bullet out to the maximum range that you would shoot. Some experimentation would be needed but the inserts are very inexpensive and can be changed/reused at will.
Most of the tapered bases than I'm familiar with have about 20moa of taper. In theory, this would get an average flat shooting cartridge out to 1,000yds without cranking your elevation adjustment to the extreme.
A related thread came up here a short while ago and you can apparently even get 20moa out of the Burris inserts if you use the appropiate sizes in the front and rear.
Just my thoughts -VH