You can pick up the head mount assemblies for under $150, I wouldn't add the extra weight of a PASGT unless you are worried about being shot at:
http://www.bhphotovideo.com/c/produc..._Assembly.html
If you prefer the helmet mount, ops core makes lightweight ballistic and non-ballistic helmets which have NVG mounts on them.
non-ballistic:
https://www.entrygear.com/product.asp?id=BASEJUMPSPORT
ballistic:
https://www.entrygear.com/product.asp?id=FASTBALLISTIC
Any updates?