Re: Good practice bass amp for funk/r &b
You'll need a bass amp with at least a 15" speaker and probably somewhere in the region of 120W. The amp will probably be solid state and thats fine for bass as you are looking for clean and plenty of headroom. Make sure that you have enough eq on there, look also for any deep low switch and make sure that you have plenty of outputs for hooking up additional speakers, headphone amps and also DI out from there. Also make sure that you have active and passive inputs for whichever bass you require.
As for amps/combos as you live in the US there are a number of manufacturers - SWR, Ampeg, Mesa Boogie etc - check out e-bay to see what there is. It is highly unlikely that anyone will have blown a bass amp because they are built to operate at higher levels and produce lower frequencies. I use Laneys, Ashdown, Carlsboro's and even Polytones when I do any gigs but not all of these are available in the US. My personal preference is using my Laney combo which has something like 650W and has a 2x10 speaker with a tweeter I usually augement this with a 15" cabinet for low end.