A 42T is an excellent choice-- paired with an 11-42 cassette, you can climb just about any hill you would come across, and the 42-11 spins out around 30mph.
The Vero will fit any traditional 5-bolt 110bcd chainring. Of those three, I would recommend the WolfTooth. They make fantastic parts. Also check out availability of RaceFace-- as good as WolfTooth, might be a little cheaper.
I run my narrow-wide chainring in the outer position on a 110bcd 2X crankset (FSA Gossamer) because I spend more time in the bottom half of the cassette than I do in the top half.
You can find some dedicated 1X cranks fairly cheap, but few in square taper, so you would also need to change the bottom bracket-- not a huge issue, as you'd be looking at a Hollowtech II or MegaExo most likely, either of which can be had for $20-30 (plus the tool to install/remove.)