With your budget and your plan to it for night hunting, in my experience at least, either go with a thermal hand-held for spotting (image intensifying- AKA " I^2" night vision just doesn't compare with thermal in the spotting department) or a weapon-mounted I^2 scope like the one Vic listed or similar. I've got a couple of helmet-mounted monoculars (PVS-14) and a 2x ATN Thor thermal scope. My hunting partners have Armasight Gen II 4x white phospohor Nemesis ($1,500-$1,700) scopes. Unless we're in very thick woods, the thermal picks things up a hell of a lot farther away than their 4x or the PVS14s with a 3x or 4.5x magnifier. Now, once I see "something" at 300-600 yards and am trying to figure out if it's a no-no (calf, deer) or a hog, the 3x or 4.5x lens on the gen 3 PVS14s or the 4x on the gen 2 Nemesis beat the hell out of the 2x thermal in that regard.
So, with $2,300, the $1,700 refurb PS24 or a good gen 2 riflescope is where my $ would go, with any left overs going toward a good IR light like the TNVC Torch or, depending on how much $, the Streamlight SuperTac IR ($80 or so).
No, can't mount the PS24 behind anything. One of the weird things about thermals is that they can not see through glass, and don't see lasers (unless it's a laser lighting something on fire).