[maxmsp] [ot] portable stage amplification

Hey all,
this is slightly OT but might be interesting for all on the list who are performing electronic music live on stage.

I'm looking for a local (not PA) sound reinforcement that should be high-quality (flat frequency response) with enough bass, powerful enough to keep up with typical (non-distorting) bass or guitar amps and with rugged design. These excludes the typical compact near- to midfield studio monitors.
Additionally it should be portable, hence the weight limit of about 20kg. Stereo amplification (or even better: modular loudspeaker cabinets) would be a plus, tone control is not necessary.

Right now i have found the following combos which look pretty ok:
- Acoustic Image Contra: 
http://www.acousticimg.com/products/prod_contra.html
- Schertler David: 
http://www.schertler.com/prodotti_ing/loudspeakers/david.htm

There are a couple of decent loudspeaker cabinets, which are also an option, e.g.
- ACME Low B1 - http://www.acmebass.com
but i'm still looking for a small and powerful amplifier (about 300W @ 4Ohm per channel), preferably mono block or bridgeable stereo, with balanced in and neutrik out.

Any experiences, ideas?

greetings, Thomas