Do a search mate.....lots of info on this subject!! However...
Its obviously advantageous to get the shocks too since they will last much longer than your stock shocks once lowered, but the TRD springs are designed to work with your stock shocks too (consider the amount your willing to spend)...I myself have the springs and rear sway by TRD and everything seems to work nicely so far. Rather invest the cash saved on shocks for other upgrades.
-B-
Its obviously advantageous to get the shocks too since they will last much longer than your stock shocks once lowered, but the TRD springs are designed to work with your stock shocks too (consider the amount your willing to spend)...I myself have the springs and rear sway by TRD and everything seems to work nicely so far. Rather invest the cash saved on shocks for other upgrades.
-B-