Gemini FAQs for you...
Q21 here. In fact have a good read of all Gemini ! FAQs. Indeed the
Gemini 1 Yahoo and
Losmany Yahoo fourms are also a good places for information.
You can bet pretty much all questions you have have been previously covered. That said, sometimes finding the info can be ....difficult.
The Plug is a Lumberg 013104, Plug DIN 4 way (just leave the lock ring off), RS
here, there are others and Element 14 has these plugs or alternates but RS has free post.
Buy a spare while your at it.
edit:
oh I didn't answer the PSU question....any +12VDC ~ =18VDC PSU. The motors run better at 16~18VDC, in fact any voltage above 12V, the system is designed to run up to 18VDC. Some users run on battery just fine but atm I'm using a computer PSU @12V. I personally don't have an issue running mine at 12V but I've just converted a computer PSU to give 16VDC out to run my system.
Maybe a Laptop PSU with ~16VDC out @ 3~ 4 Amps max out would suit. If not Jaycar has PSUs.
edit edit:
Also be careful with the Motor DIN connectors. Ensure you put them on the correct way wrt to the DIN socket and plug key. If you don't, you can put +12V on the motor encoder +5V lines damaging the system motor encoder ICs. Just sayin!