I am going to guess this is for your '96 and unless you have modifications you really do not need to upgrade. you already have a regulated return fuel system (the 99+ do not) IF you have a good mechanical fuel pump then the stock setup works very well until you start adding lots of power. Shimming the pressure regulator can be helpful in stabilizing the pressure a bit higher.
Pretty much all of the kits out there are going to be in the 1k-1200 range. I've heard good things about the kit from Beans diesel Performance, he uses stock SD pumps so in the even that one goes out somewhere you can pickup one easily at the local parts store.