HNG 64 is a 64bit 3D arcade system created, obviously, by SNK. It's a JAMMA board, similar to what you would expect from an MVS board, though it only came in a single slot variation.
Screen shots aren't too easy to come by, as the Hyper was never emulated, nor will it likely ever be.
How many games were made?
Here is a thread you should take a look at. Discussion of how many games and what they are.
There is no HNG console. The HNG suppoesdly can be CONSOLIZED like you've probably seen MVS consolized. Super Goose may be able to assist with that, though I'm not sure.
How expensive is it? I bought mine direct from Vektorlogic (just do a search in the Hyper forum or visit
Vektorlogic's website). I bought the board and the 4 fighters. It cost me $465 shipped to the US via EMS. Evidently you can do a little bargaining, though I did not.
It may sound high priced, but dammit, it's worth it!
And don't be confused by the 3D SamSpi game on the PSX. THAT is NOT a port of an HNG 64 SamSpi game. The only game ported to a system from the HNG64 was Fatal Fury: Wild Ambition.