I think something class D and powerful will fit the bill. I use a TC BH800 which is great, especially because using the compressor helps beef up the response of the board over the whole range of the bass. I turn the hi-mid and treble controls off so only the bass gets through to the board, but with the comp you still get plenty of rumble on the G string too.
Whereabouts are you, you're welcome to come and try mine.