Jawbone and that caliber Bluetooth are great but if you want to fill a kitchen with sound and a good computer speaker you don't need to spend that much $.
As suggested above, check out Amazon or even Frys online if you don't have a brick and mortar. This summer I got a $20 Bluetooth speaker at Frys with a 3.5 input.
I used it in my backyard at poolside all summer playing Pandora and Jazz Radio. It had more than enough power, in fact it was never at full volume, nor was the iphone. Check out some of the lower priced speakers, I think for your stated demands they will do the job.