Big Macs (!) and PCs are actually alomost exactly the same under the skin now and can share expansion cards / peripherals.
What Mac seem to be doing at present is pricing thier full size machines very competitlvely, they always cost more than a similar pc but top spec macs look to be a great deal at present.
http://store.apple.com/Apple/WebObje...VMI0oq1GMW1fpU
Two dual core Xeons - that is one fast computer. Spec it with 2 big drives and you will be in editing nirvana.
I am sure one of the cheaper macs will do the job fine but if you can afford it this is the baby.
I would buy one in a snip if I had the cash and run xp on it (shame it looks like a fanheater ).
__________________
I have two prejudices - I am anti HDV for consumer camcorders, and I eat mooks who claim to be pro wedding vidders and ask dumb questions.
www.zaskarfilms.com You tube channel 'zaskarfilms'
JVC DV5001e (big cam), Sony PC6E (tiny cam), Vinten pro5, PAG light, SM58, Sony ECM50, Sony C-76, 0.5x convertors for sony, Rode video mic, Vegas 7.