How to find out what kind of base and rings you need to your scope on your rifle?

I have a Remington 700 sps tactical and Nikon 4.5-14x40 scope to put on. What brand and style should i use?

Personally i like the Leupold 2 base dual dovetails, it gives you great access to the bolt and chamber even with a 90 degree bolt, rock solid and you don't need the rear windage adjustments enough to get them-especially with a good scope. The scope defines what rings you get-if it is an inch or 30mm tube, how high the rings need to be (you should be OK with mids or highs-not extra high). I have a 50mm Objective on my Bolt and with XH rings it has a little bell gap.
Of course there Weaver systems and Warne makes great products too-not used them but I like the look/mechanical properties of them. But I'm just partial to the Leupolds. You can take the rifle in and try different set-ups;that is sound advice so you can get it right and get the eye relief set. You need to decide if you are lapping the rings if you decide to have a shop install-not a bad option so you know the scope is true and not binding. And since most scope hardware is installed with internal wrenching screws to INCH/Pounds and not Foot/Pounds it might be cheap insurance to have a shop do it.

Your rifle appears to be drilled and tapped for a rail. So for the most part you can pick whatever kind of rail you want first, screw it down and then find the rings that will work with your scope. In your case, I would probably just get a picatinney rail for it, then a one piece medium height scope mount and you should be fine.

It was pointed out to me by a grandson not long ago that there's a thing called an instruction book and reference book and etc; BING your rifle make and yadda and see what the book calls for.