I'm ready to get into the NV world and I've got an existing PASGT helmet that I'd like to start as opposed to just a basic bump helmet.  I've already upgraded the pads to an Oregon Aero set and it fits me well and feel comfortable.

I know the Norotos Rhino mount is readily available and designed for this helmet using a J-arm to attach a PVS14 but is it possible to use this mount with a dual tube or bino setup?

Would I be better off buying a 3 hole shroud and drilling some holes to use a different mounting option?

Are there any recommended side rails that will fit and work with the common accessories; I think I remember reading that some are proprietary fitment?

The mount needs to be compatible with the arm you use: either bayonet or dovetail. I’d suggest going with a dovetail setup especially if you’re planning on using BNVDs. I believe all BNVDs use dovetail mounts; PVS-14 you can get j-arms with the bayonet interface but again, it’s better to just start with the dovetail system.

With the PASGT, you probably only have a one hole mounting system and to use any of the larger 3-hole mounts you’d need to measure and drill the mounting holes. I know there are updated single-hole shrouds/plates and if I was dealing with that, I’d stay with them. I imagine it’s pretty difficult ensuring the 3 holes are drilled with no cant, in the right positions. I have my old ACH from when I was in and it has the old single-hole mount on it. I had no problem locking in the Norotos LoSto or Wilcox G24.

Anecdotally, I grew up wearing the PASGT and while I never had anything except the old suspension system and leather sweat band, the ACH was a gift from God in comparison. I would suggest looking for a decent ballistic helmet that’s either ACH style or higher cut that comes with a 3-hole shroud installed. It will be much more comfortable, have better aftermarket parts, and most likely provide slightly more protection.

the Rhino 1 is bayonet only ( shitty ) the Rhino 2 can be converted to dovetail style and would work fine with bino's if you are trying to save some cash.

I understand the suggestion to just buy a new helmet but I'm not at the point of wanting to spend $1000 on a new one just yet.

There are sub $1k ballistic helmets. A new ACH should be nowhere near that, a used one probably can be had in the $300 range. There’s also this at $450 with a modern shroud and rails. Big discussion on it here.

Also, someone else with more knowledge can chime in, but I do not believe any of the main stream rails will fit on a PASGT helmet. The rails use the mounting screws for the chinstrap and those are not there on a PASGT. I know you mentioned BNVD usage, but I’d budget some money from that into a more modern helmet. It will solve all the questions you have helmet-wise.

That Danmark helmet certainly piques my interest, seems like a good value.  Now I'd need to come up with a way to explain to my wife why I now need a different helmet than the one she bought me (unsolicited) less than a year ago.

I don’t envy that. Perhaps explain that with the PASGT, while a nice gift, will cost more money and do less than if you front a little bit more and buy something purpose built?

Or just buy her something nice first.

Also, there’s at least one OpsCore for sale in the NV EE forum for around $750. I would think you can find something worthwhile for under $800. But, like I said, an ACH will do what you need (will fit rails, updated chinstrap/pads, will fit earpro) for cheap. It looks like even brand new it’s under $500, used surplus was around $250.

That Denmark helmet looks like it is under $400 now with the website discount code and free shipping.