I like the 3.75" over the 3.25". For one the more suspension lift you have the more likely you are to need a transfer case drop, or a sye and dual cardan drive shaft. For two I was never a fan of spring spacers. I would avoid buying their shocks since they are awful. I would also add a motor mount lift to help correct the rear drive shaft angle and minimize the need for a case drop. Pick up a set of bilstein shocks, some bump stop extensions, extended sway bar links, a rear track bar bracket and you aee on your way to a decent lift.