could be bushings, could be shocks, could be springs not on the rubber perches anymore.
if its A) you need a bushing puller to get them out, and urethane squeeks so you would need high quality greaseable urethane
B) need new ones
C) need to re-seat the springs
crawl under there and take a look. if you dont know, take it to a shop. theyll tell you
**I have sigs turned off, so if you're asking for advice based on your mods, I can't see them**