Do NOT get the 18x UHDs, too much magnification and the clarity really suffers.
The 12x UHD on the other hand are far and away the best model in the UHD line, and I’d go so far as to say they are comparable to Swaros in terms of edge to edge clarity and resolution (though you do give up some magnification).
That being said, the 12x, especially with UHD glass, will be more than enough for PRS spotting.