This is late, but...
Good choice!
In my experience, Macs are nice, and pretty, but limit your choices. Say what you want about PCs, but you can do anything on Windows, and in a lot of cases, for free. Also, Mac OSX crashes no less than XP when you're actually trying to do real work. In my time in the IT industry, I've seen as many issues with Apples as any other computer. And, as an ex Apple repair person (haven't worked on them in years) I can say that Apple hides manufacturing defects instead of recalling products with known issues. Don't ask your local Apple repair center, they're hindered by a non-disclosure contract, if they're even in business. Apple *competes* with their service centers, too. Maybe not as much now since they were sued. Maybe my personal experience or the experiences of my customers has made me bitter, but I expect something when I pay that much for a piece of hardware.
And no, I'm not a Windows zealot. I'm a disappointed Linux zealot.
I own both Macs and PCs, although I'm finding less and less excuses to power up the PowerBook. Windows "just works" for me. Use whatever "just works" for you, but I think a PC is a good choice. My Dell has run flawlessly since the day it came out of the box and the XPS models are extremely quiet. Also, the organization I now work for uses about 25000 Dells, both workstations and servers, and they're workhorses. Just don't buy the cheapest thing you can find. If you build your own, protect the equipment from static. Home made machines are notoriously unreliable because of poor equipment handling. You can damage a piece of equipment and not even feel the static discharge, or know you damaged it until weeks or months later.
(If it's not *just* for presentation, which is entirely possible. I'm not too impressed with what I've heard about them.)