I think it would be an up hill battle to convert the the audio into a digital format suitable for QM. The best solution would be to obtain some QM transmitters to mount beside the RXs. You probably have some in the system and should be able to obtain more quite inexpensively. You will of course have a lot more Cresnet devices which will have power and hub considerations. DIN-HUB is inexpensive and there are heaps of QM-WMCs on fleebay.
However, I assume you have control over the TVs, therefore obtaining new low powered amps with optical in, or analog if the TVs have it, would be the tidiest and the best long term solution.
Lindsay
