Non HDMI reciever hook up advice

Just upgraded to a 55" Panasonic GT30 Plasma and have the following components hooked up.
1.) NAD T754 non HDMI reciver
2.) Plasma to NAD ( Optical)
3.) Plasma to Denon 2910 DVD ( HDMI)
4.) Plasma to DirectTV (HDMI)

I have a old Monster optical toslink from the Plasma to the TV.

What is the best way to get the best sound from this set up. I would buy another receiver if I can sell my current one but if I can;t should I atleast upgrade to a newer glass Optical cable (Wireworld Supernova or equilivant)? Thanks....
I'm assuming here that your sources are then DirectTV and the DenonDVD. The best option for hookup would be SPIDF or RCA-style digital. Toslink would be second.

I'd run all the HDMI connections directly to the TV. Then I would run the digital SPIDF to the NAD and switch the audio through the NAD and switch the video from the TV.

A simple way to do this instantly would be to use a Logitech remote and setup both the TV and the NAD to auto-switch to the correct inputs based on activity--like "Watch DVD" or "Watch TV"
The only caveat that I have is some tv's will not always pass through a dolby digital signal to your receiver. In that case you might have to go from source to receiver for audio instead and then use HDMI for video. My brother-in-law's tv wouldn't do it.
You are right Dlr, I had to use HDMI for video only and optical for audio. Thanks