YFZ shocks are an easy upgrade.
there is a writeup on the 2nd or 3rd page of this forum explaining with pictures, how to install them.
i'm very pleased that i upgraded to them
i just couldnt justify spending the outrageous amount of $ it costs for Works or Elkas or the like. drag race shocks for my Camaro were'nt even that expensive
you should be able to find a nice set off EBAY for around $250 give or take a little depending on condition
they are a taller shock then stock tho. and have read that they put your ball joints at a not so optimal angle, but i have yet to read of any failures because of them. also from what i know, they only seem to work with stock a-arms.