I have a Single PM G5 too, and I've had it for 3 years now. It's a snappy computer for everything such as internet, music, photo editing(photoshop 7.0 max) and some light video work. But now as I get into video editing more seriously, I can tell that my system takes FORVER to encode video.
I would go for a 24 inch iMac, highest spec.
Hey G5Unit, I heard that if you are getting seriously involved with editing not to go with imacs... It wouldn't be the best concerning many factors and espacially the upgrades thinking longterm less cost. More people could tell you why but check your moves carefully. Btw, thanks for the replies guys!
Well I am just a high school student, I'm not setting out to start a business.
Guys, i think you should NEVER go for an iMac over a Mac Pro for real video editing, unless it is for funding-restricted class rooms, etc... They make good design machines, but the lack of any expansion really limits them.
Video takes a lot of resources and optimizing over a standard setup. Ideally, you would want to have a separate, fast system/applications only HDD, Large storage HDD's (500Gb would be a good starting point), at least 4GB of ram, video out to a tv monitor, etc...
While an iMac will fulfill some of those needs and has some pretty high processing power, and with the recent addition of more FW connectivity may be good for students, it does not offer what pro's or serious users will need.
One obvious lack is an express card slot or expansion slot - meaning you can't move to eSata, which is where a lot of video is moving these days for fast external storage or raids for speed.
These are just a few of my warning thoughts. Imacs
can do video, and will be fine for certain circumstances or needs, but as far as longevity is concerned, it is doubtful to be able to continue to fulfill the needs of a main editing machine for 3 years or so. A little more money invested now can save you a lot later in terms of money and capability.