Lowering vs. Ride vs. Hauling?

[C10N.UT]

Hi all;

I was wondering about how to go about lowering my 86' swb GMC.

I was planning on a 2.5 spindle for geometry sake,and not to sure on the rear half.

My plans are to use this truck for a daily driver,albiet on crappy Utah pothole infested roads.And to tow around a buddies and mine 19 foot jet boat,but still maintain a decent ride and be able to pull that trailer?

I read somewhere about new rear springs that suppose to smooth the ride and lower the height.I would like to keep from cutting into the anything if at all possible,eg frame or bed.