You have to first ask yourself, "do you like the way it rides stock?" If you are satisfied with its stock ride and you just want a small lift, do not buy OME.
I did just the same exact thing with our 02 sport 6 months ago. I spent $800 for a set of OME springs/shocks and it rode just like an old go-cart, it was super stiff (and we bought the "comfort" set-up) bone jarring over every little bump.
We kept it that way for a week and then bought some 99 coils and Trekmaster shocks and took out the OME. (99 coils are slightly taller than 02's)
It now rides MUCH better and other than a 1.5 rear spacer to correct the dreaded Toyota rear sag, I will not change it until I go to a Sonoran Steel 7.2 kit.
If you are going to run front and rear aftermarket bumpers then OME is the lift for you, but my "personal" preference was more of a factory stock ride without the stiffness.