Hey,
I mostly listen to the early jazz that you mentioned. I've been through many vintage speakers speakers and amplifiers for many years. It's actually a lot tougher to get right than you'd think. Out of the KLH, AR, Wharfedale, EV, Universities that I've owned and auditioned, none do as well as a properly updated pair of 3-way Bozaks. Why? Because of the aluminum cone, 6" B209B Bozak midrange. It's ability to bring forth vocals and horns is legendary. Exceptional depth, clarity and precision that you can hear within a few moments. I wouldn't suggest going any smaller than a pair of Rhapsodys, they're 2 cubic feet. The next step up are the B302A's, they're approximately 5 cubic feet. Yeah, a little on the large side. But all these fall within your price range. Which by the way, is darned important. Oh, and Bozaks are efficient. You can get what you need out of them easily with a 30 watt amp. Right now, I'm using a GAS Grandson amp that is rated at 40 watts. Bozaks are revealing, so you do need some decent amplification.
Biggles