If you have a computer with VST Host then you might try some of the free software out there that allows you to load your own samples. I did play with SuperDrumFX (SDFX) on my PC and loved it, it is a software drum sampler.
see:
http://www.superdrumfx.com/index.php?language=2 I remember a user here on MagaDrum, ignotus, suggested "Hydrogen"
see:
http://www.hydrogen-music.org/?p=downloadIf you dont have a VST Host on your computer then you can seek out a free VST Host and use ASIO4ALL to drive it.
I know this isnt what your question was asking for, However I posted it anyway just in case it becomes helpfull. I myself would love to see a DIY stand alone sound module.
- Bean