Thanks for the replies.
I have considered the DB25 to RCA option, and Rotel will send one here to the local Rotel dealer in Oz for around $60. However, from what I gather on some other computing oriented forums it may be possible to simply upgrade the PC's vid or audio card and bitstream audio to the AVR via TOSLINK or COAX. I'm not quite sure what formats would be available via toslink but I assume just standard 2 channel PCM stereo, and standard DTS and DD?
I'm quite unsure what to do as I know that if I want any HD audio, I must use the Rotels analog (DB25) input. From what I gather certain HD sounds can't be bitstream due to copright protection? Also i'm pretty happy with the standard DD and DTS formats and have nothing to compare to make a choice.
Btw if it helps the AVR is an RSX-965 and i'm not interested in upgrading atm!
Is it worth going up the HD audio path? Will it be noticable on my modest system?!