Oh yes, thank you...
I would like to stay within $2500 but if need be I will go higher. I was also wondering if maybe adding a good fast external hard drive would help me when I have a lot of video to upload and sort through.
If you're REALLY serious regarding your video editing, etc...then a Mac Pro is the way to go.
Brand new...the least expensive Mac Pro is $2499. But it's only a quad-core model...and thus not that much better than a quad-core iMac (other than more internal storage options, multiple video cards, can have two optical drives, lots of ram upgrading, etc.). Here's a refurbished 8-core model for $2649:
Refurbished Mac Pro 2.4GHz 8-Core Intel Xeon - Apple Store (U.S.)
Apple is supposed to come out with a new Mac Pro model soon (this rumor has been around for quite a while). If a new Mac Pro model does come out...I'm sure it will be super expensive. So unless you're willing to SERIOUSLY increase your budget...there is no need to wait if you wanted a Mac Pro (get a refurbished 8-core model).
I know that you mentioned that portability would be nice...but you are concerned about performance. The graphics hardware in the iMacs is usually better than what is found in even the best MacBook Pro. So if you are serious about your graphics/video work...then an iMac would be better than a MacBook Pro for this type of work. Plus the 27" display on the iMacs is awesome! Lots of screen real-estate.
This is not to say that the quad-core MacBook Pro's are "slow-pokes"...just that a quad-core 27" iMac may be a bit better when it comes to graphics performance. If you're willing to compromise a little bit on graphics performance...then a MacBook Pro could be an option.
But if a Mac Pro or MacBook Pro is not for you...then getting one of the 27" iMac's would be the way to go (starting price about $1799)!
- Nick