Stay away from OME springs. You will absolutely find that they'll bag out within months.

Since this is a mild lift, you can run the stock coils with a spacer in the back then adjust the preload on the 5100's to achieve your ride height goals. This set up won't perform amazing offroad, but you would have selected something other than an entry level coilover if that was your goal, right?

As for the question of uca's, you will need to upgrade if you're having problems getting your alignment back in spec, or require the extra caster to clear 285 or larger tires. If you plan to stay at 2", or with the 265's you should not need uca's