best 4.5" midrange drivers under $1K

This is the only thing I can think of that nearly meets your specs is ACCUTON C²79-6.

I would not design around a tweeter.

I'd start with midrange first and then find tweeter and woofer to match.

Sure, AudioTechnology 4 & 5" Flex Units. They are poly cone and run $240-287 each and most important, you can run full range with no x-over to over 5Khz.
You'll need a 3rd order x-over @6Khz for the 4" unit.
If you make a pair, can I come over and listen?

If you use accuton that low then I'd use two per speaker.

I assumed you wanted metal/ceramic instead of damped designs like paper/poly/fabric.

Another option Jordan JX92S - this will be comfortable in the range you require but it will roll off a bit in dispersion above 2 KHz.

@shadorne: yes I understand what I'm trying to do and I'm willing to pay for it :D I wanna something non-paper, so anything like poly/carbon will do. paper is too laidback of presentation to my likings as non paper will do a clear straight forward presentation. Accuton can go low in 4" size? I think theyr good at upper midrange freq but ok i'll put that on my list :D thankss

@cdc: Flex Unit is on my list. Thanks en sure u can listen

anybody else wanna throw something in mind?

I agree with the AT Flex-Units. You may find this driver's frequency response/construction hard to beat: (http://www.solen.ca/pdf/audiotec/4h521306.pdf)