WaveBurner Pro will do all of the above
WaveBurner Pro sounds interesting to me... Looks like the app is pretty hard to track down though. I've tried searching a number of sites, but come up empty-handed. As best as I could figure out, v2.2.1 would have been the latest version for OS 9, but I'm not even sure of that.
If you're seriously concerned about high quality playback, i.e. the real audiophile playback, you should consider doing it in OSX and, preferably, on Intel Mac.
Feel free to share any details on how you feel it shines. Or what set up is needed to make it shine. I'm always open to learning, although I also know opinions vary from person to person on what constitutes "audiophile" sound.
I've actually tried Mac OS X many times over the years. Mostly on Intel processors. Unfortunately, to me, it was a let down. I sense we may have different primary factors when it comes to what constitutes audiophile sound.
For me, having an unbloated OS is a primary consideration, and this project (ASIO on Mac OS 9) makes sense in that context.
My initial impressions of OS X actually were positive. I felt it had a more natural audio presentation than either Windows XP or Windows 7 did.
And I can understand why that presentation might be a primary factor for some people. Unfortunately, with more listening, it was a let down for me because of the greater "bloat" of OS X compared to other OS'es like Windows. This is something I've pinpointed based on lots of testing and listening to music across every platform: Windows, Mac OS X, Linux, iOS, Mac OS 9, etc - the rule holds true for me everywhere. If you open Activity Monitor on OS X and Task Manager on Windows, you can compare the number of running threads and processes and Mac OS X has more "congestion". But I was already hearing that in the music before I looked it up. The 2nd issue is a little more ambigious. On OS X the audiophile players can utilize something called "exclusive mode" and that's the only high end option. Why is that the only option? How does it compare (on a technical level) to options in Windows such as ASIO, WASAPI, or Kernel Streaming? Without really knowing the details, it comes across to me as a lack of serious development on the OS X side.
Anyways, I found I preferred any of those 3 options in Windows to exclusive mode in OS X, but it's hard to tell if that's just because of the bloat in OS X. Then I found I usually prefer ASIO over all the others, and Mac OS 9 happens to have that.
As far as the "bloat" issue goes; it's a primary factor to my musical enjoyment. Through lots of listening, I've learned that I enjoy music a lot more on lighter OS'es. When the OS is really lean (less going on in the background; more dedicated only to music), I tend to "just enjoy the music" whereas when the OS is bloated I tend to get bored and get listening fatigue really quickly. Then I usually change tracks a lot and end up listening to very narrow genres. I find I can be more forgiving of other shortcomings when I have this one thing, as long as the other things aren't too bad.
I also notice other benefits of a lighter OS as well: more fine details, more atmosphere, better "blackground", etc. many of these differences show up especially in longer listening sessions after my ears settle in. But I always pay attention to the boredom vs engagement factor and the biggest determination of that for me is having a leaner OS.
Anyways, having said all that - now you know where I'm coming from.
I'd definitely be open in hearing what you appreciate about OS X for music playback, and what steps you recommend to get the most out of it.