Problem, looking for a external controller for DAW software while connecting a MAC and PC to work in harmony:

My systems:
AMD64 @ 2.8 (crushes 2.5 in terms of vst plugins)
AMD XP 2800

Looking for a controller device, with or without FX.
Would like to use Digital Performer, Pro-Tools or Logic (or express on MAC) Would like to use the AMD64 to control the EWQLSO Platinnum orchestra as well as Giga Studio 3.

Would like the main sequencer to be mac based.

My thoughts are if I do this right, I should be able to MAC-tize my working enviorment, have some sort of DAW controller, and yet, tie in my AMD64 to access the VST plu-in instruments.

I would appreciate two scenarios:
1) Budget minded with a MAC system that can grow, starting with a 1.8 G5
2) Money no object scenarios.

PS. Bottom line, ACCESS the AMD64 POWER VST intruments and use MAC as sequencer, and added controller.

thanks