Generally, get the lowest ones that you can get comfortable with. Another thing that you might consider is how much internal elevation adjustment your scope has.
I'm only mentioning this because you mention shooting at 100 yards. If you decide to go out to farther than 100 yards, you may run out of adjustment. With a 50 yard zero, I have to dial in roughly 8 minutes of elevation to get to 100 yards and about twice that to get from 100 to 150.
If you plan to shoot farther than 100 yards, I'd suggest getting a mounting system with at least 20 minutes of elevation built in.