you know depending on the cost of the inlay you might just want to buy yourself a jem. Check out some of the auction sites and some of the guys selling em around here and compare it to how much getting your RG to look like a jem. The margine of difference might be just 200 bucks or so, if i had the choice i'd go with having a real jem rather than just an RG that wishes it could be a jem
Go to projectguitar.com and see what the folks say there but expect the vine thing to cost at least $300 and by the time you get to all the other mods, esp if you want a proffesionally done paint job you'll end up spending more money than if you just got a Jem on evilbay.
Funnily enough I am just in the process of finishiing off a long term rg to Jem mod. During this time I actually bought a Jem, but never mind. I am doing something pretty unique (more of this in a few weeks), and that is the only reason for modding an rg to jem IMHO, otherwise save yourself the hassle and expense.
As dex says it will cost more to do an authentic jem. But alot of the work can be done yourself, and the projectguitar.com tutorials are the best I have found, and produce excellent results, I am a complete wood working noob, and the managed to talk me through all kinds of jem mods.
If you are in the UK, I could probably tell you some luthiers that have quoted me to do the body modifications, and some other useful contacts.