I think the Nitek shares the same innards with the Apeks Quanum, Tusa Hunter etc.
I've got a mate with an Apeks version for sale, at a very reasonable price.
To be honest, you've got to ask why you want a gas switching computer. I'd guess that the Nitek shares the same drawbacks as my Vytec - an awesome computer, but for any dive using mutliple gasses that involve decompression stops, you just can't see what the deco stops are in advance...... you just have to blindly follow the computer and hope that it all works out.
For deco dives with multiple gasses, there really is nothing better than a VR2/3. The simple fact that they let you look ahead at what your stops are puts them in a different league than the Vytec, Nitek, Quantum, Cobra2 etc. IMHO, the gas switching on these are just toys, not a useful function. Using them as deco computers is going to lead to tears eventually.
If you're not doing deco, then what's the need for multiple gasses?