I'm in the process of developing a relaxation package called Alpha 15. The basic idea is to provide a way to eliminate stress in both body and mind in a very short span of time. So, no matter how busy you are, you can still enjoy the important benefits of conscious relaxation. The fundamental program element is a 15 minute guided relaxation and you can try it for free at http://www.matthewsigmon.com.
The program utilizes audio signals called binaural beats which help your brain to synchronize to a specific frequency, in the case of this program it's a deep alpha brainwave state (8 hz). So all you need to make use of this feature is a pair of stereo headphones (the best set you can get your hands on). A deep alpha state is ideal for experiencing profound physical and mental relaxation without simply falling asleep.
If you do try it out, please drop me a line and let me know how it works for you. Also, repetition is an important part of learning to relax, so feel free to use it as often as you like.
I don't see why not, David. The program is strictly audio and isn't dependent on any particular approach to breathing. Similarly, interacting with whatever biofeedback information you're getting would be compatible as long as the process didn't involve an audio component. If you try it out, please drop me a line and tell me about your results. There are currently some free downloads for ambient music on the site that would likely work well with the therapies you've mentioned. Help yourself!