What picatinny rail MOA to get??

[WelcomeNate]

Below are the rifle, scope and Rings I plan on getting (want to get able to get Barrett BORS later on also) Not sure what picatinny rail cant I need/should to get.

1) I want to be able shoot 50-1000 Range (.308 cal). Is 0 cant fine, or do i need higher (0,5,10,15,20)?
2) What would be the benifets of doing one over the other, and/or if there is more then one option.
3) Since I'm going with higher ultra rings (1.4") what kind of different does that make if any?
4) What are the higher end brands out there, not even sure what brands to start looking at.

$1115 Remington XCR Tactical Long Range .308 (84461)
$1075 Leupold Mark 4 LR/T M1 4.5-14x50mm 100 MOA Matte Duplex 30mm (54660)
$192 Barrett Zero-Gap 30mm Ultra High (1.4") (13324)

More details the better, and an explaination as to why. Would love to learn in the process, and I'm sure there will be more the one option/opinion. I thank you in advance for you time and answers/responces

 

[Broz]

You cant go wrong with a 20 moa Nightforce Rail for the 700 Rem. Badger Ordinance also makes a good rail as does Near mfg.

With a 20 moa rail it should leave you with roughly 70 moa of up elevation and plenty of room for a 100 yards zero.

There are cheaper rails too, but I feel this is definatly one of those things where you get what you pay for.

But, yes a zero cant rail will get you to 1000 yards with most calibers and a scope with 100 moa. But I say why not go 20 moa in case you ever want to send one to a mile?

Jeff