best bookshelf speakers for < $2000?


I have Studio-20 V5s on stands right now for my living room 2.0 music system and, while I like the sound, I need more bass extension.
I don't want to add a sub due to room clutter concerns.   So, I am looking fro an upgrade from my Studio20s.
I have been looking into towers but now am thinking, why not stay with sand-mounted speaker since I have the stands already.   This is for 2ch music only.  My amp is Emotiva UPA-2 SS amp.

Would I do better to go towers or go higher-end bookshelf speakers?


The towers I've been looking at have been 
Salk SongBirds/Towers
Ascend Sierra Tower
Silverline Prelude Plus

Thx.
albireo13
Right now the room is 14' x 30'but, we plan to sell and downsize this year so room will be smaller
What does have deep bass is Dynaudio c1s and totem mani-2s.  Really impressive for monitors. I am sure there are others. Both require lots of power
For a smaller room,I can recommend Nola Boxer 2's. I feel they have more than enough bass. I love everything about these speakers. They don't require a lot of power, and perform beautifully! (but that's just my opinion) If you can audition a pair,they should be on your list.
the larger Paradigms won't take up much more floor space than the 20's and stands...beyond that there are many great small to medium floor standers and larger/better monitors...