Re: Rings and bases for LR setup
Pretty sure Zeiss turrets are IPHY on that scope, not MOA.(mine is anyway) As far as the set up, If your scope has 68 MOA total travel, its safe to say that you half of that available for "up", if your currently mounted on a level base. That says about 34 MOA is left for elevation, which is plenty to get you to 1k.
My LR guns sit on 20MOA rails and hold 200 yd zero's. I would suggest a similar set up to you. The extra 20 MOA in the rail will not hurt you if you want to maintain your 100 yd zero, but will give you the extra adjustment range should you decide to stretch things out.