I Implore you with all my heart please take your time in deciding what platform you want. If you're buying a mac because you think it'l be better for designing purposes…think again..a pc can do anything a mac can do plus has a greater range of software support and..with that much money you could buy a superior superior pc spec..(macs are novelty imo, most Architectural offices actually use pc's, theyre cheaper and easier to maintain provide a faster platform for cad and redering intensive work, also they're more universally friendly interms of peripherals ). The same could still be said for Web/graphic design and for everything else you might do. Pc's have come a long way.......and in todays time, mac's aren't any more stable than a pc environtment. (I know since i've used both and appz on mac crashed just as many times on this platform as they did on pc (Design appz anyway i.e photoshop, flash/dreamweaver).
If you're solely deciding on platform because of your work...I think buying a pc spec for x amount of money is probably a better choice you'll just be getting a more powerful workstation to do all you're work from.
If you really like mac's, find the their OS more comfortable to use and in general just favour macs more...no problem buy what you enjoy using..just be aware of their mad prices...and extra costs involved.
Im not a pc fan boy I do love macs and all apple stuff..< Iphone, IPod, I pad...just when it comes to macs..nah
