Need help creating lead tone

Hey all,

I'm looking for advice from anyone good at constructing tone for lead. I'm putting a cd together at the moment and have to re-record all of my demos along with a few new tracks, get them mastered and then send them off to a few labels.
Here's what I got:

Guitar: Ibanez Jem "Bad Horsie" (just got it - best guitar I've ever played)
Pickups: Dimarzzio Breeds
Amp: Marshall 100DFX
Hardware: PODxt
Hardware: Digitech GNX1
Software Environment: Cubase SX with Tascam US428 controller interface

All the above plus a kick-ass PC with a bunch of plug-ins.

The sound I'm looking for is closest to:
Marty Friedman's lead on "Rust In Peace"
and/or
Theodore Ziras www.theodoreziras.com "Virtual Virtuosity" cd (apparantly he got his sound on the POD xt)

Basically I need a very thick, warm sound that accentuates swept arpeggios by allowing the different tonalities of each string to shine through. Also for fast legato work I need a sound that helps to reinforce the clarity of individually picked notes - I usually achieve this with a light noise gate to reduce subtle background noises such as a palm moving across muted strings etc. I don't mind playing bridge or neck pick-ups, the ones on my new axe are amazing at any setting so input on pickup settings is also cool.

I know a lot has to do with your style of playing etc, I've been playing guitar for a long time and do have a style that I can call my own. All I need now is a good sound!!!!!

Any help is much appreciated

Forgot to mention, I also have a Line6 DM4 stomp box. The best lead sound I have come up with to date is the screamer run through the amp with the amps own reverb and delay... Anyway, the distortions on that stomp box may help to create the tone, or they may not...

Yeah I know, I had a crap set up going through regular stereo speakers. It sounded fine on my home set up but crap everywhere else. Anyway, I got a new guitar so the muddy sound from the stock pickups is gone and have spent a bit of cash on a new pc.
I've yet to put any of my new stuff up with the new gear, it sounds a lot better now but I'm still not happy with the actual tone for lead (heavy chunky riffs are fine using the Rectifier on my Digitech). I'll let you know when I get my latest track up, could do with some feedback;-)