Jabba, got couple of questions... do you have air con in your room? Have a really good (but pricy) system in mind but heat maybe a bit of problem
IMO, wireless lan is probably not a good option for you since I can imagine interference being a problem in uk. Security is always an issue too.. so, gigabit network is probably a better choice wit 1000Mbps. The 54Mbps will probably end up being 2-3M/s in real life, it's way too slow when you have to transfer video files around. Someday, I have to upgrade my 100bt lan to gigabit, hate to miss a show cause you can't transfer few gigs of avi's to another box in time
Do you mind having less than 3 LCDs? Cause matrox parhelia isn't exactly the best choice for video editing.