I'm interested in getting some aftermarket levers for the bike, but there are none available for the gs500.

Reading the site, it's suggested to replace the clutch lever assembly for the GSXR or SV650 clutch lever assembly.

Is there a write up on how to do this?  What all is needed?  It's probably pretty easy, but messing with something I don't know about is intimidating at first.

Thanks for the help guys!

It should be a direct swapout.  Remove the clutch cable, unbolt the assembly, bolt the new one on, and re-attach clutch cable.

I like these and like them. But there are better ones out there for other bikes.
http://cgi.ebay.com/ebaymotors/BANDIT-GS500-SV650-SV1000-MSR-PRO-RAPTOR-CLUTCH-PERCH_W0QQcmdZViewItemQQcategoryZ35587QQihZ017QQitemZ270197664778QQrdZ1QQsspagenameZWDVW

so the "perch" is what i'm looking for?

The perch is the part that actually bolts to the handlebars and it is the part that the housing of the clutch cable butts up against.  You most likely want both the perch and the lever, additionally, new these items normally come as a set.