Im in the sane boat as you poorboy, I have been buying my parts one at a time that way the total cost doesent hit my wife all at once, other wise it would be a hard sell.
Im going with the SLR lift, I too am new to the Xterra 4wd scene. SLR seems to be a good product ( if any one knows different let me know), I have also bought products from Calmini which seem to be equally good. The selling point for me on SLR is one the schocks and the fact their leaf spring pkg. is one solid piece and they will build it to my specs at no extra cost (i.e I want my pkg. leaf spring that is, to be able to handle 4 adults and an extra 200lbs or so of gear). Yes I know that type of set up will be rough riding on a unloaded vechicle but that is fine with me. It's a 4x4 for gods sake.