Just thought I would report in for those of you in the same boat.
Ended up using some good quality RCA adapters like this from Jaycar:
http://www.jaycar.com.au/productView.asp?I...=&SUBCATID=
Then got myself a good quality 6 channel cable similar to the Vector I had and hooked it all up.
After a couple hours of testing various scenes from both Blu ray and HD I can say that the exercise was a great success.
No problems with audio at all, no clipping, drops outs, lower volume levels and no discernable difference using the adapters in the receivers 5.1 analogue outs. Beat paying stacks for the Zector switch.
So for those of you with two players and only one receiver with 5.1 outs, this is the way to go. The only caveat being is to use good quality audio cables. I think this makes all the difference.
Steve