I need to get rid of my JBL 4311s don't I?


I have a pretty decent system and can't help thinking that my 70's JBL 4311's from a radio station are holding me back.
I have them perched on some leadshot filled Target stands...toed in about eighteen inches from the wall. To my ears they sound great if the vinyl I am spinning is great. They seem to be a very revealing, flat, near field monitors. What speakers should I be checking out as replacements? I have an ARC Ref1, VPI TNT 3.5, ARC Ref Phono, ARC D130, old Cardas Hexlink interconnects. My local hifi emporium has a pair of used Quad EL63's that they are asking fifteen hundred bucks for...I listen mostly to jazz...lots of mono....and soul from the 60s...any suggestions? I am not concerned about cost but do like to get some bang for my buck. I have considered going all out for Wilson's, Revel, or B&W but really don't know where to begin. My next purchase is certain to be some kind of monoblock tube amplification but I guess that is for another thread. Thanks in advance for your suggestions!
ntscdan
thanks for all the suggestions...the speaker connections on the back are pitiful...especially for a pro speaker...the foam around the tweaters is starting to disintegrate and re-wiring the innards sounds like a good idea...I think I will put some effort into "fixing up" what I've got before I shell out any more dough...
I recently partially rebuilt L150's. I changed the binding post filled the innards with a newer filler and rebuilt the woofer surrounds. They are a little tizzy on top but they aren't bad at all. I think dynamat on the inside walls and cleaning of the potentiometers will find you a new and improved speaker for little money.
I've just bought JBL 4315, it sounds much much better than my current modern Quad 22L in all aspect.

Anyone heard 4315?
You also mentioned wanting to purchase some kind of tube amplification in the future? That being the case, why not see if you can arrange to bring your JBLs along when you begin to audition the amps you have singled out for audition? This will not only allow you to hear the results of that sort of combination, but it will also allow you to talk to various dealers about the sort of speakers they might suggest & hear the speakers they are using.
Man, don't give up your 4311's. Many feel those were the best loudspeakers ever made. There is no better way to get bang for your buck than to use JBL studio monitors. Comparatively inexpensive, but almost all the major (and minor) recording studios used those speakers when recording the albums you listen to. What better speaker to have than ones which will give you the same sounds the artist was mixing on?!! I have a pair of 4311's as well as classic 4412's (with freq. adjustments). The 4412's (which are still sold w/o frequency adjustments) are the only thing I'd recommend, and it's a close call as to whether they sound better than the 4311's. Even though the 4412's have a titanium tweeter, the cone tweeter on the 4311's has an amazing high frequency sound. People are clammering to buy 4311's on eBay so don't think for a minute that you're missing out. My 4311's and 4412's whip the heck out of $10,000.00 Vandersteen speakers my friend has (in my opinion). Moreover, I have a high-end, modern system with various Sunfire signature components, and my JBL's sound just find with them.