As stated, the 1200F rear wheel is a straight swap, but it's the same diameter so wouldn't get you anywhere. Well, what I mean is it wouldn't lower the bike at all, obviously it would get you wherever you were riding ...
As for the front end, I don't see it as being feasible. I've done a lot of work on a 1200F and let me tell you, it's really hard. Things you don't expect to be a problem suddenly turn out to be insurmountable. In order to keep the ABS you need 'split' callipers, well the left one anyway and that means off another Honda which kinda limits you to the 1200F, But they're 130 mount spacing. Good luck finding forks to suit those.
Anything can be done, but at a cost and I don't think £1K would get anywhere near. Sorry.
If you just want to lower the bike, try the lower seat. Then look into lowering the back end to 1200F levels. I suspec that's just shock, but I could be wrong. Then just push the forks up through the yokes to match how much you've lowered the rear. I think you could make it a LOT lower without spending too much. Might look a bit odd though.
Don't forget you'll lose ground clearance, most noticeable might be the footrests, but maybe not. I think there's plenty to spare unless you're tracking the bike, which as a CrossTourer is unlikely.
Having said all that, I'm thinking you could swap everything over to a 1200F front end. The frame is probably the same but it would be possible in any case. You'd need the F callipers, but I think they'd work ok with the rest of the X braking system. You need the F front wheel too, so probably a rear to match. Probably need the F front Wheel Speed Sensor. Either would work, but cable outlet is not the same so you'd have trouble fitting the wrong one for the fork - at least and still have sufficient cable length. And you'd need the ABS ring from the F. Ah, how many slots in the X ring. If it's not 50 then more problems and ABS may baulk at that.
As I said, many problems. Have you thought about just buying an F and taking the fairing off like I did?