Thanks Andy, thats helpful.
I personally much prefer fixed wideangle lenses so am happy to focus by scale! I'm thinking of getting a Canon 30D together with the Canon 20mm f2.8. If my maths works out OK this is the equivalent (roughly) of a 28mm lens on 35mm. One day I'll scrape enough cash together to get a full-frame 5D and use the 20mm to its full wide potential, maybe adding a 28mm f1.8. One day.
I'm kind of sad to be going digital, I hope to run my film outfit in tandem with the new Canon as long as I can, but emulsions keep getting cancelled and I am getting nervous! I'd better jump to digital before I'm pushed by my favourite films ceasing to exist. If Fuji ever cancel 35mm Provia 400F my film Nikons will be obsolete.