Congrats on the Satch, AxSport4me... The Satriani is my fave Ibanez guitar now; the neck is really nice on that guitar, and not so very different from some EBMM profiles...
Which brings me to the "which EBMM for Joe?" Q: Joe's IBZ has a more "vintage" neck than is typically associated with Ibanez - 12" radius, pretty deep D - almost V - shape, as I recall - and if asked to pick from the current EBMM production stable, I think he'd probably be most comfortable on a floyd-equipped Morse - in fact, I've seen pictures of him playing one on stage somewhere, tho' I can't for the life of me find them now.

Anyway, I'm pretty sure Joe would want a more traditional neck shape than what's found on the JP model... Of course, it'd be great to see Joe leave the Ibanez camp for EBMM, but it would seem somewhat unlikely - I'm sure Ibanez treat him very well as one of their two or three primary endorsers...
re: the JSX - if they ever make a 50 Watt version, I'll consider it, but I sure as heck don't need 100 Watts where I'm playing!