I second the recommendation for ProAc's. While I am not familiar with the 1scs, I recently heard a pair of Tablette Reference 8's, which had incredible low end for their size (10.5" tall). Their price is quite good, too, and at $1,200 list per pair, you could still afford a decent subwoofer. However, for $500 (list) more, I ordered a pair of the Tablette Reference 8 Signatures, which go even lower (38Hz, versus 40Hz) and supposedly sound much more than $500 better. Also in your price range would be a pair of used Thiel SCS3's, which are rated to 46Hz, but sound even lower, and have great detail and imaging.
And I agree, that to get good deep bass, and still have main speakers to fit the size of your room well, monitors and a powered sub are probably the way to go. Most floor standers that are properly scaled to your room are probably going to need a little help in the low end to meet the goals that you are stating, so they could use a sub as well. For floor standers, new Thiel CS1.6's or used CS.5's (or 1.5's), Totem, Meadowlark, and ProAc come to mind.
Tom.
And I agree, that to get good deep bass, and still have main speakers to fit the size of your room well, monitors and a powered sub are probably the way to go. Most floor standers that are properly scaled to your room are probably going to need a little help in the low end to meet the goals that you are stating, so they could use a sub as well. For floor standers, new Thiel CS1.6's or used CS.5's (or 1.5's), Totem, Meadowlark, and ProAc come to mind.
Tom.