Not trying to be negative, but your looking at the wrong scopes, for the wrong caliber, for a defined (by you) need that the equipment YOU selected cannot fulfill.
You are selecting scopes based on: the quality, clarity, and price.... and then talk about shooting small varmints at ranges up to 600 yds.
How about looking at scopes that fit the functions you actually have planned for the rifle??
In a 270 @ 600 yds using the best long range bullet made for 270 caliber, the 150 Berger VLD, sighted @ 100 yds your drop will be in the neighborhood of 77", and your drift in a 10 mph breeze will be around 25". How are you going to compensate for those pesky facts, and actually hit your target, without any means to easily and repeatedly adjust for elevation and windage on the fly in a field environment??
In other words sir, spend some time to read about external ballistics possible at range, for your chosen cartridge; it's actual drop and drift with varous bullets; read some about scope turrets, zero's and how they are used; and get some familiarity with the utility of using a reticle for hold over and hold off. In other words you need a little self education in long range shooting, and there is plenty to learn and read about here.
Good luck...
