Don't know about the U.K., but here Apple sells refurbished MacBook Pros with the same warranty as new -- you can get last week's Pro model at the price of a no-firewire Macbook.
I've used both 15" and 17" models extensively and vote for 15" if you're gonna carry it around a lot.
I have a new MacBook Pro, they do have one FireWire 800 port. I bought a 9 PIN/4 PIN Bilungual FireWire 800 cable from Monoprice.com ($5.90 ... so nice a price I bought two), and use that to connect the camera to the computer. Then I conect my external hard drive to the computer via the USB 2.0 port. Worked just fine.
How does everyone like the new MacBook Pro? I'm thinking of getting the
15-inch 2.53GHz. I'll be adding lots of software, including Final Cut Pro (hopefully). Have you heard of any major differences between going with the 7200-rpm over the standard 5400-rpm? I talked with a sales person at a local Apple store who said a customer actually returned his MB Pro loaded with the 7200 and changed it back to 5400 because he said it "'vibrated loudly and was noisy."