gen1 REALLY isn't good for walking around, too much fishbowl effect, but most importantly you need to refocus it constantly. But it's good for a riflescope.
Your options are this:
~$800 for a gen1 riflescope that allows you see about an extra 10 feet into every treeline, clarifies open fields, and allows you to see anyone's IR light and lasers, and a cheap class 1 IR laser with no windage or elevation adjust.
~$2800 for a gen2 monocular, helmet, mounting options, and a cheap class 1 IR laser that has no windage or elevation adjust
(nobody ever mentions the cost of strapping your nvd to your head, or aiming with it)
The sub $1800 gen 2 tubes can be REALLY shitty. Like as bad as the top end of gen1 shitty. The additional gain is disproportional to the amount of noise in the tube and it usually has the same resolution as a gen1 tube. Although you can see more, it's difficult to identify anything due to the noise.
The top end gen2, like the SHP and HP tubes, work very well. Only a bit less resolution than gen3 and with more noise. But they work fantastic.
Comparing my top end gen2 to gen 3 OMNI VI, in super dark areas they're quite similar in performance. Obviously a bit easier to identify stuff in the dark with the gen 3, but you're not losing a whole heck of a lot. The main advantages of gen 3 are in the autogating, and the fact their peak sensitivity is in the normally available IR light at night.
The night vision you buy is based on the people you play with. These guys will all recommend you dump $2200 on a gen2-HP right away or you'll get owned by everyone else with night vision. Well if nobody in your community has night vision, don't worry about it lol
I ran a gen1 yukon riflescope for years, and although the gen2-HP is a significant improvement, the gen1 riflescope was still much better than the naked eye.
MFG's will usually state the eye relief of their NVDs. For a riflescope you'll probably want something in a 3x, the zoom will help with the fishbowling.
And most of us just use ballistic glasses to use with NVD's.