Would the 28h hold up on an XTR hub you think with two small panniers and a bar bag?
Neither will take a rim brake. As you know. The 28 would need to be on the front, but then if you are putting a disc brake on it...which is OK XC and CX racing but a bit touch and go for touring / every day with luggage. I'd use tough spokes and I carry some spares :)
Crest and alpine are not the most resilient of rims either so you'd need to be careful with spoke tension and whatnot.
Not much room for error, really.