During my weeks of daunting NV research, I came back to TNVC time and again as I gained knowledge. Starting at zero and reading everything from there, learning some of it, retaining some of it ... my final conclusion: "There are so many ways for a NV neophyte to get screwed with this gear, the majority of your effort should be invested in finding a supplier you can trust!" Identify your needs, then go to a trustworthy supplier.
I bought my PVS-14 from TNVC. Absolutely love the unit.