You got it just right -- it's like WalMart for music gear. I've bought a lot of stuff from them, because I know what I want and they have good prices (they can afford to, because of the volume of merchandise they move) and a good return policy (return anything within 30-plus days for a full refund, no questions asked). The return policy is really helpful, because I think you need to spend some time with most music gear to really get a sense of whether it's working out for you -- trying it out in the store only gets you so far.

For a performing system, I realize money and portability are factors, but don't ignore the way it sounds. The all-in-one systems (Crate acoustic amps, etc.) frequently don't cut it except for on-stage monitoring purposes, because they don't have the projection or the spatial dispersion that you get from having two PA speakers at either side of the stage (or of the performing area, whatever it consists of). Think about what size room you'll need to fill (i.e., the biggest gig you expect to play), and how much volume and "body" you want your sound to have (I realize we're talking small-scale acoustic music here, but you still want the sound to have a little "meat" to it). Some of the systems whose main selling point is portability really don't move enough air to sound good, and if (when) you try to "push" the system they can sound horrendous.

For small acoustic gigs I use a Mackie mixing board with on-board effects (used sparingly), a QSC power amp, and two JBL TR125 speakers on Ultimate Support tripod stands. With microphones, stands, cables, etc., it probably cost somewhere between $2000 and $2500 (U.S.). This is probably more bulk, and more expense, than you're after. But it fills the room, sounds great, and hasn't broken my back (yet). After a lifetime of buying, selling, and cursing my musical equipment, I have come to the conclusion that you're better off spending a little more at the outset to get something you can work up to, rather than going cheap at first and immediately discovering the equipment's shorcomings. Ultimately, it's cheaper to buy the good stuff once than to buy the cheap stuff over and over again. I just wish it hadn't taken me so long to learn this lesson. Good luck.