PC audio tweaks?

Alright - based on what I've read in this forum the last couple of months, I am on the verge of tossing my CD player and going to a server based system. Specifically, I plan to go from a G4 Powerbook to a Waveterminal U24 to my existing MF Trivista DAC. In fact, I've already ordered the Waveterminal and a Terabyte hard drive.

My question: are there certain tweaks to keep in mind in setting up this system? For example, should the the G4 and/or the Waveterminal be on an isolation platform? Points? Rollerblocks? Would the G4 or hard drive benefit from power conditioning? Should the digital noise of the G4, hard drive and Waveterminal be isolated from the rest of my system in some way? Is there any difference between one USB cable and another? Should I sprinkle all the digital components with Macedonian nun urine and sacrifice a goat?

As you can see, I've been thinking about this to an unhealthy extent. Anything you can do to straighten me out would be appreciated.
I just got an iMac GT connected by a stock usb cable to a Wavelength Brick USB dac. It sounds great -- way better than my Exemplar/Denon that it replaced. Both units sit on my Samson rack, and the DAC is plugged into my BPT power conditioner. (The computer and external HDD are plugged into different wall circuits.) Beyond that, I have no plans to do the audiophile trip to the computer and usb cable. -- David
My iBook G4/TwinDac stack sits on a Townshend sink...everything seperated by cones or Final Labs bearings. Also, I have a sheet of Stillpoints ESR paper between computer and dac. Try listening to the G4 running off battery...you may hear a lower noise floor (one less ground loop)
Thanks for your helpful responses. Are there no differences between USB cables? According to Monster's website (I know, I know ...) their USB cable is better because it is shielded and has a bigger power wire for bus powered devices. Probably just hype, but both of those things would seem like they might make a difference.
Steev --- It's very possible that the Monster tweak could work. For now I'm just concentrating on getting all of my CD's ripped (I've got about 800). If you do try it, please report back. -- David
USB cable differences? AFAIC, when you're in digital-land, especially when it involves data (perhaps except the RedBook CD format), data integrity concerns dictates that what goes in at one end will appear at the other, but if it doesn't, the error-correcting codes transmitted will ensure error-free data transmission.

Imagine for example, your digital camera transferring images to the computer with different results with different cables. Now doesn't that sound absurd? Also imagine having an external drive connected to your computer via USB that will show read/write errors using less-expensive USB cables but no errors with expensive USB cables. Digital transmission should just work, 99.99999999999% perfectly, on any approved digital cable, except when the planets lined up and their rays hit maybe...
Power the waveterminal from battery. These other tweaks will pale in comparison.