I just purchased a Remington 700 SPS in 308 w/ 20" barrel. I have a Bushnell Elite 4200 6-20x50 scope and am wondering what base and rings would be the best (within 200.00). I have been looking at the Leupold Mark 4 1 piece base and the Burris Extreme Tactical rings. Is this a good combination and if so, what height ring would I need (short, medium, high)? I appreciate any help.