Re: J-custom MRG-4 and MRG-5...beautiful must see!
Those are some custom one off's Ibanez made for Kurosawa this year. Last year Kurosawa had a bunch of custom RG8520's made. Gurj actually just bought a used one off Ishibashi (he's got pics of it at the "show your j-customs" thread). If I recall, the MRG models are all custom/special models made for Kurosawa-gakki, HRG are custom models for Ikebe-gakki and the YCRG's are for Yamano-Music.
Dunno how many of these "custom custom" models are out there, but every once in a while Guitar Center gets something like that done. (ie. the Texas Prestige models and various other exclusive models).