"If you pay peanuts you will get monkeys..."
For your present budget, you're best going for something like the ZeroDAC or something similiar...
If you can afford a bit more, then the Musical Fidelity V-DAC is half decent...
You can use the Asus Comparison Utility for that...
Along with the differences that it shows, the "E" uses the Marvell 9128 for SATA6, whereas, the Premium uses the 9123, the 9128 being better...
It hasen't been available in the UK for some months, so "yes" it does seem to be discontinued, however, decent alternatives would be the Asus P5Q Deluxe or Gigabyte GA EP45 UD3LR which are available.
If you are happy to go for a "used" one, I would have a look in the "For Sale" forums on the...
I run an Asus HD5850, Q9950 @4.0GHz, 1 SSD, 3 HDDs, 2 TV cards etc on a Corsair VX 450w PSU without any issues...
A "quality" 450w PSU will handle it without any problems, but a cheap "generic" one will definitely not...
I like to have the OS (Windows + Programs folders) on one partition and data etc on the other (D: ) partition as it make it easier to make backup (and restore) images of C: and splits data from OS.
The fact that I can have this kind of "organisation" is an important advantage (for me...
I've used 2 x 80GB X25-M G2s as both separate HDDs and in RAID0 and I prefer them in RAID0, fast as they are as separate HDDs, there is a nice increase in RAID0, especially seen when moving/copying large (video) files. I have the 160GB RAID volume partioned into 2 of equal sizes (74.5GB each)...