FYI, I just noticed that Acon are now selling R930 receivers individually for US $60 in their store. Previously your only Acon option was to buy a transmitter/receiver pair (for $120).
R930 receiver (1 unit)
I can't say that multi-flash radio P-TTL and/or HSS will work - with for example one R930 transmitter and a few R930 receivers, since I only have one R930 TX/RX pair to play with - but it might.
Also new in the Acon store since I last visited is the interesting
R930II transmitter / HSS converter trigger pair (US $120). This is basically a R930 trigger that has been modded to mount below your existing Nikon radio triggers and let them think they are mounted on a Nikon camera, even when you are shooting with a Pentax body.
The R930II can also function as a normal R930 compatible Pentax PTTL HSS 2.4 Ghz flash trigger/receiver.