Unislot in HDX900

Folks,

I would like to take advantage of this wireless setup and have googled but am not clear on the workings of the unislot.

Can a wireless receiver in this slot handle two channels of audio -- in other words -- record output from two wireless transmitters worn by two different people?

Or if this is not technically possible in the unislot, can two people with two receivers be recorded on one channel -- mixed?

And for any HDX900 owner out there -- what is a quality unislot transmitter/receiver for this camera?

Thank you,
JR