I would recommend a used pair of Revel Studios. Your $4K budget is just enough to get a pair. They are nearly full range, as they go down to 30hz, and with room reinforcement, they will sound full range. These are very accurate speakers, and the bass is very quick and tight, and not boomy at all.
Check out the glowing reviews both online and in stereophile (see link below):
Stereophile Review of Revel Studio(FYI: Kal Rubinson, the Stereophile reviewer, bought and used these as his reference for a few years.) I lived very happily with them for five years before moving onto the Eggleston Andra IIs.
I will state that they do need a fair bit of power though. I recommend 200 wpc, but 100 wpc will do, if it's a very powerful 100 wpc (i.e. a beefy solid state amp, and better yet, monoblocks). I started out with the Levinson No. 27 (100 wpc), and while it worked acceptably, (the bass was a bit loose), upgrading to the Mark Levinson No. 23 (200 wpc) was a definite improvement, as the bass tightened up, and the speaker seemed to open up very nicely.
My two cents worth.
Good Luck in your search!