I thought EMCCDs usually clock in at around £15,000 so they are a bit of a niche market. Hope you manage to find a donor.
The QE can be very good – and some go out into NIR (1.8micron) but many are stuck with a maximum integration of 1/25 seconds, a slightly unpredictable gain control and an 8 bit output format. So for dim targets its probably actually cheaper to co-mount 2 OTAs and use 2 CCD cameras at the same time (arranged so the start of readout of one initiates the integration of the other).
Nice idea though.