Hi, With my sound engineers hat on I would use a small PA. mixer, amp and speakers!!!!
For quality you need a full, flat frequency range system with good headroom.
I assume this is for your own listening, when using an acoustic kit?
There are one box solutions.
- Drum amps. Like a monitor wedge with an amp, Roland do a PM-10, Various other makes are available.
- General purpose powered wedge.
- Keyboard Amp, these are full range and available in various sizes.
- Bass amp with high frequency driver (tweeter), not the best but will have good bottom end.
- Powered or active speaker, much like a powered wedge, but a different shape, needs an input volume control.
All these systems need to have large bass units, 10 inch minimum, and will be in mono. Two will give you stereo,
How loud depends primarily on the sensitivity of the speaker. But manufactures insist on selling things by power. Worth looking this up.
At a couple of feet away, 20 watts should do it, with high sensitivity speakers, more likely you find most things as above start at about 70 Watts.
Good luck, I hope I have widened you choices a bit.
All the best, Chris the Fader.