If you're not set on a powered mixer, and are willing to spend a bit more, you might want to consider the following combination:
http://www.behringer.com/RX1202FX/index.cfm?lang=ENG http://www.behringer.com/EP1500/index.cfm?lang=ENG

This is what I've mated to my Tyros2 for gigs. I'm very satisfied with the system's flexibility, power and performance. Ultra low noise -- signalwise, that is. The amp has a cooling fan that is a bit noisier than necessary, but is easily and inexpensively replaced with a quieter pc cooling fan. Excellent frequency response. Fantastic flexibility in both the mixer and the amp. (Use Google to find reviews on the amp.)

For even more power, consider the EP2500.

If weight is a concern, though, be aware that the mixer's weight is 6 lbs and the amp's is 34 lbs. Mounted in my Grundorf carpeted rack case along with a Furman RackRider power distributer, the whole package weighs in at just over 50 lbs. Since I don't do a lot of gigs, and make good use of a handcart when I do, the weight isn't a big concern for me. I can certainly see, though, why the pros look for lighter equipment.

Charles

[This message has been edited by cwalkeralso (edited 12-29-2006).]