...and that's probably the most succinct but relevant post on the forum! At least, for anyone looking to build roughly this size machine. It's taken me about a month of trawling the forum to come to pretty much the same results that Jazz has given. I'm looking at a cutting envelope of around 1300x700 so that I can comfortably machine the outside of a quarter-sheet of panel material.

You might try to skimp on the spindle as you're unlikely to need that power. Don't, because what the 2.2KW spindle gives that the next size down doesn't (and for not a great deal more money) is an ER20 collet which will take up to 1/2" shank cutters. That can be really useful.