Efficient floorstndrs. to reach above furniture

I'm getting nowhere except frustrated trying to fill large space with sound from Silverline 17.5 monitors. Subs didn't work. I'm now soliciting suggestions for efficient floorstanders with drivers located near top of cabinet to surmount obstructing furniture. Space is: 17 X 30 w/ 10 foot ceilings and adjoining 2 - storey entry. Power: Creek Creek 5350 se., which I may have to upgrade. My total budget for speakers and more powerful amp is
$ 4000.00 (used). Thanks!