Upgrade PCs While Using Pwr Conditioner?

I had been using a RGPC 600S power conditioner with its stock PC. I will have my Teres 320 TT/Accustic Arts DAC and Drive/Tron Syren pre/Audiopax 88 monos to (potentially) run into it. I have not yet upgraded any of the stock PCs, including the cord on the power conditioner. I have a dedicated outlet/circuit for my audio equipment.

I could use some advice on optimizing my power delivery. Do I (a) keep the RGPC 600S, but upgrade only its PC, (b) ditch the RGPC and upgrade each component's PC, (c) keep the RGPC and upgrade ALL PCs, or (d) not be so friggin obsessed and just enjoy the music?

If the power conditioner is working correctly, why would one need to have upgraded PCs for the components plugged into it.

You will receive a larger benefit from installing another dedicated AC line so you have one line for digital components and one line for analog components.

If that's not in the cards, then you will potentially hear benefits by upgrading your stock power cords depending on the overall resolution of your system. From a basic level, upgrading your power conditioner's cord and your amp's cord to a 9awg cord will reap benefits. Also, despite its deceptively low cost, the Volex 17604 cord available from Carlton-Bates.com could be a nice upgrade on your front end components.

You could also be less obsessed and just enjoy the music. :)
I wouldn't plug the amps into the RGPC. Front end components OK but the amps may not be a good idea. I tried that unit and the amp with it sounded a bit weak on dynamics.
If you want some conditioning for the amps, try something that doesn't restrict power, something like SHunyata Hydra2 with a good power cord will probably be better choice on your amps. Or upgrade power cords on the amps and have them plugged directly into the wall.

Even with power conditioner in place, the upgraded power cords on your components will make a difference.
The first question I would ask myself is does the power conditioner improve the sound. If yes, then I would go on to the power cords. But in all circumstances I would not obsess over it and just enjoy the music.

Actually I would take Tvad's suggestion and install another dedicated line. Then move onto power cords and unless you can prove to yoourself the conditioner is needed I would forget about it.