Since this is a hunting forum for the most part, the word "tactical" often implies characteristics that may make a particular "tactical" firearm less suitable than a "standard" in the field. Weight is often the most significant of these. "Tactical" firearms tend to be heavier than their counterparts.

One of my rifles is built on an out-of-the box Remington 700 LTR (.308, 1:10, 20"). From the beginning, it's turned 1/2 MOA with M118LR ball, thus delaying to some degree my initial plan of an aftermarket barrel. Nonethless, with the heavy barrel it was heavier from the start than I'd want to carry hunting and became even heavier after I parked it in a 1.5 AICS and topped it with a Mark 4 6.5x20 ER/T. I should note here that this rifle was intended for the KD range almost exclusively - not for the field.

Your intended use isn't clear here. If you're going to hunt with something like this, I'd recommend the 700, but more likely the SPS. If you want to stick with .308, I'd stay with 1:12. The SPS stock isn't the greatest, but affordable aftermarket stocks abound for the 700.

If you plan this rifle to be used at the range only, you may want to shop some other forums more dedicated to those purposes (sniper's hide, etc.). And - be prepared to shell out some cash, a fully-utilized "tactical" rifle will chew through more of your budget than will something meant for the deer woods.