If you had 7000$ish would you get a Macbook Pro loaded with a cintiq 21ux
orrrr a Dual Quad core Mac Pro tower 2.66 with alot of ram and a sweet video card… to run Zbrush and Maya.
anyone…
You should get a lot of RAM either way…
The rest of the choices should really be derived from your work habits.
If you travel much or do presentations to clients a powerbook makes sense.
If you mostly work in the same place, or do much batch work the tower will be faster for you.
If you’re primarily doing zb or ps work the Cintiq is great.
If you only do a little ab/ps work, and more frequently in maya or compositing apps - you might want to score an intuos4 and a couple nice panels.
Re: the sweet video card, be very sure you need it - you can sink a ton of money into them very quickly (especially with macs) and depending on your workflow may or may not reap equivalent benefits.
Personally, I’ve had both , but stick with towers - they’re faster, easier to work on, more expandable, and on top of which I don’t travel much, and do most presentations via pdf. I’ve also had the Cintiq - but for a number of reasons (primarily it’s size + weight) I don’t prefer them. Am comfortable enough with my 12x9 intuos3 and a pair of 23s.
Either way it sounds like your about to have a lot of fun! 
If you dont have to be mobile…get a good tower. As far as Cintiq…I’ve used one at work and can say that they are a bit overpriced for what you get, dont get me wrong though, If someone else was paying for it, I would request one! The money you save on not getting a Cintiq can go to ram/videocard, or drugs and hookers.
But with $7,000.00 your gonna be happy with either.
The Cintiq isn’t going to be portable, so you might as well go with the Tower.
Unless you’re dead-set on a Mac, you can get more for your money from a Windows-based set-up. (The last time I did laptop pricing, you’re going to end up paying a lot extra for the Mac.) I have both Macs and Windows laptops here, but we’ve been steadily cutting over to Windows machines as the software support from our vendors are better (Adobe, Autodesk, Pixologic to name a few.) I only recommend Macs if you absolutely need Final Cut Studio or Logic Pro. (Premier and Cakewalk are adequate substitutes in the Windows environment.)
Currently our ZBrush setups are quad-core systems (mostly the new i7 chips from Intel) with 8GB of RAM and Cintiq 21UX on the desk. Almost all systems are dual-head with a second 21" monitor. Our laptop-based systems are 17" Core2 Duos with 8GB of Ram. We lug around Cintiq 12Wx’s when on assignment, which while are a heavier solution than tablet PC’s, work out better for us. (The “working on airplanes” is somewhat of a myth. The test of our setups is how well they work on a job site–such a cubical–or how well they work in a hotel room.)
We try not burn more than $400 on the workstation Video cards (overkill for Zbrush which doesn’t leverage the GPU much, but helpful with Modo and Maya.) The high-end $1000+ stuff is sure cool, but we never saw the ROI. Laptops we use come equipped with the 9800GT chipset from nVidia these days. We find them adequate.
For ZB, no less than 6GB of RAM should be the rule, but with ZB4 just around the corner, that may change.
-K
Yes, please let that change small_orange_diamond