Personally I wouldn't use a nail trimmer wheel for a few reasons.
A wheel with a nail trimmer insert won't have holes in the track, and because of this and the fact that gliders pee and poop while they run it will get nasty fast.
Nail trimming tracks really don't seem to make to much of a difference, my girl had a wheel with a trimmer insert and I never noticed any difference.
If you leave the trimming insert all the time it can actually cause some discomfort for the glider as it'll rub down the skin on their feet.
Wheel wise I've got a steal wheel and it's wonderful and extremely well made.
When it comes to nail trimming I'd suggest to slowly acclimate your gliders to you touching their feet, then introduce them to clippers, only doing a nail or two at a time. Over time they'll get used to it, especially if you offer special treats only during nail clipping time.