I would go for the XT stuff no matter when you buy. It's lighter than the XTR and is tougher (in my experience).
I don't know if it would be needed, but the MRP Link is a really good addition to have (mrp.com) but the '02 has a version of it...don't know which is lighter or performs better.
You don't need the rear lockout. You need a front lockout- if it doesnt have one, I think you can buy the lever for about $80? Rear lockout isn't needed on this suspension