I have some Gen 4 NV, and have played with alot of stuff.
So I can give you some good advice on what to get and what not.
DO NOT GET GEN 1, save your pennies untill you can afford gen 2+, thats when you will really enjoy your purchase.
Also, get a monocular, you will thank yourself for it down the road, your ability to mount it on your weapon, or head is great, and its easy to adapt to the monocular, unlike the goggles.
Honesty, go to your bathroom, grab two empty roles of toilet paper, and put them over your eyes, and look how much of your depth perception is lost.
Then try with just one roll, you will see a huge difference.
Hope that helps.