I've been a fan of the iMacs for the past few computers I've had. (Original bondi blue, indigo, and finally the Aluminum.) I can't complain about the computers. They last a long time, look great, and don't really need much expansion anyway. You can change the hard drive as technology improves and larger sizes are needed. RAM can easily be added but I doubt we will need 4 GB for at least a couple years but it can of course be added for very cheap by the time that comes around. (Cheap now too in some cases).
I'll be honest. I would love a Mac Pro as I love computers and fixing them up, but I don't really need the extra power and cost of it and unless you do it won't help you. The price difference between a good mid level iMac like the 20" 2.4 GHz model $1525 ($26 for 1 GB crucial RAM to make it 2 GB) not including any discounts for education and the low end Mac Pro ($2299 and add 50 if you need wireless) could be invested in a high yield online savings account for at least 5% APY and easily pay for itself on another far better iMac in a few years. You have to factor in the screen you would need and you should really get an LCD and not use an old CRT screen. I'd say hold off on that until cinema displays are updated and perhaps they will be cheaper and have the isight built in.
I'll be honest. I would love a Mac Pro as I love computers and fixing them up, but I don't really need the extra power and cost of it and unless you do it won't help you. The price difference between a good mid level iMac like the 20" 2.4 GHz model $1525 ($26 for 1 GB crucial RAM to make it 2 GB) not including any discounts for education and the low end Mac Pro ($2299 and add 50 if you need wireless) could be invested in a high yield online savings account for at least 5% APY and easily pay for itself on another far better iMac in a few years. You have to factor in the screen you would need and you should really get an LCD and not use an old CRT screen. I'd say hold off on that until cinema displays are updated and perhaps they will be cheaper and have the isight built in.