Well, I should have fixed my abhorance of a mistake! Thanks.
I was lucky enough today in getting an old but still venerable Canon 35-70 mm lens that will do the trick. Tried it out on my own 40D and it seems fine - at least Kay Burley's mug came out in focus anyway!
The shop assistant at the camera shop was telling they have all ready have a nice few number of firm orders for the 5D Mk III.
Wish I was that lucky!