If you have £1500 to spend then neither of the bikes in the original post would be my sort of choice, but it depends on the sort of riding you intend doing. I like lists, and checklists especially, start the list with any deal breakers and refine as you go:-
tyre size and clearance - are you planning on going remote enough, and rough enough, that 26" would be a better choice than 700c? How big a tyre do you need/want to be able to run?
brakes - rim or disc - if rim do you need canti/v bosses - if disc do you need the rear disc tab chainstay mounted
frame material - speaks for itself
suspension - all, some or none?
bars - flat, drop, somewhere in between or the ability to switch around?
frame fittings - front and rear rack and guard mounts, number of bottle cages, do you potentially want to run hub gears, etc?
I went through something similar and ended up basing my build on a Salsa Vaya frameset but I don't anticipate remote touring or especially rough touring. The frames good enough for cross riding so will cope with all my needs. but it has front and rear rack mounts, clearance for up to 700x44 tyres, disc brakes with the rear on the chainstay and is made of steel. It ticked all the boxes except for ability to provide chain tension for hub gears. I decided to go with the frame and try one of the mini EBBs for chain tension, so far I'm glad I did.
But at the price you're looking then you could consider a custom steel frame, or an OTP with a few minor modifications.