Best cyclocross bike under £1000 and other CX chat

An XT rear mech, 38t chainring and a 11-30t cassette should provide almost the same range as I currently have with 34/44t chainrings and a 11-28t cassette, though obviously with bigger jumps but I think I can deal with that.
.

Why use an XT mech? You can use a 10 speed short cage road mech with an 11-30 no probs.

You shouldn't have much problem if you went for a singlespeed chainring without ramp and pin (which cause chain to derailed without a derailleur.

Don't listen to Ed.