I've found on my long actions that the Picatinny rail is probably the easiest way to go... If you are going with a 0 MOA rail, then you might need Medium or Medium high rings. I have a Bushnell 4-12x42 on my TH XP 30-06 and it does allow me to adjust my scope for LOP.

My scope is still in the same rings that the XP package comes with.