Amarra for iTunes at RMAF...

Yes they do offer a demo/trial version:
http://www.sonicstudio.com/amarra/index.html

I just ordered the Amarra mini, I'll have to check it out.
It's currently 10% off as a RMAF discount, don't know how long that will last.

The mini version is supposed to be identical in sound quality as the full version. Note that it will only support sample rates up to 24-bit/96kHz as opposed to the full hi-rez formats that the full version is capable of. But for those with dacs limited to 24/96 like myself, it's not an issue. It's also my understanding that one could pay the difference and upgrade later to the full version if they wanted to.
For anyone who is interested, here's a link to the currently available RMAF 10% discount page:
http://vrsaudiosolutions.com/rmaf

Mrjstark, you're welcome. Here's the Mini info page if you haven't seen it already:
http://www.sonicstudio.com/amarra/amarra_mini.html
Mine will be here next week too.

Antipodes_Audio, thanks for your thoughts regarding mac/Amarra implementation. I am also using an Empirical Audio Offramp 3, with a Locus Design Axis usb cable from my mac mini. The mac mini is upgradeable to 4gb of RAM (it will only utilize 3.5gb of that), and I have done that with mine, which I use as a music server only. I would guess there are a lot of people using the mini as a music server, due to it's unobtrusiveness. I keep my mini on the stereo rack and run a cable from it to the tv on the other side of the room, and use the tv as monitor when needed. So, no monitor on the stereo rack.
Regarding converting your files to 24 bit and storing them at that rate, what program do you use for this? I'm getting ready to rip some standard 16 bit cd's and may try what you're doing. It sounds logical, although I'm not fully convinced it would be beneficial.
BTW, do you use the Amarra mini of full version?

Blindjim, you are assuming that Amarra only works with asynchronous dacs or the Weiss firewire dac, I believe you are mistaken. But yes, it is Apple OS software.
BTW, thanks to all, a lot of good info here in this thread on implementing computer based audio.

TBG, let us know how it goes with the Minerva, sounds like a good combo.