I came across this nicely priced unit tonight: http://sewelldirect.com/Ultra-miniat...ier_specs.asp?

It comes with an included 24V AC power supply and appears to be lower distortion, more powerful, and more versatile than the venerable SI T-amp. Spec sheet says 15Wrms in stereo, but it's bridgeable to 30Wrms mono. Both configs yield 0.05% THD and 115dB S/NR. It's really tiny at about 4"x3.5"x.75" high, so would be easy to fit into just about anything.

Here's the somewhat sparse spec sheet from the manufacturer: http://www.amphony.com/download/pdf/dsheets/A100.pdf

If the specs are to be believed, it appears to be a better option than the SI T-amp if you need a bit more power but want to maintain the small form factor the the SI T-amp is so famous for.