Re: What upgrades can be done to RG550 genesis
If you have the pickups the only difference is the high pass filter on the volume knob that rolls off some of the bass to clean up the sound when you roll back the volume knob. Otherwise an RG550 is pretty much a Jem without the decorations. Regarding the clean sounds, the Jem/Evo middle single is actually worthwhile if you want clean sounds like Vai, it's a pretty unique sounding single coil (which many people don't like) and it pairs well with the Evos.
Still, priorities, the RG550 single is fine, worry about your amp/rig situation.