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
Yea, the room is so much a component of a system. The room can dictate speakers which in turn dictate an amp. Not to forget ones personal tastes in the synergys.  

That's a huge reason I like near field listening.  I also love what Richard Vandersteen does with the Quatro's on up.  Tunable bass is a HUGE component in helping so many of the bass issues that rooms have. Especially that darn 60hz buzz most rooms seem to have.  I hear that most of the time in demo rooms at stores.  I don't 'know why rooms that are built for sound have that problem, but most seem to.  
I'll add to the confusion.

I own Sierra-1s and love them.  They're now in the bedroom system.  Long ago a bass-playing friend listened to them, and preferred them without my subwoofer.

I owned Vandersteen 2cs, and should have never let them get away.  I loved them.

I now own Spatial M2 Turbos.  They're the last speakers I'll ever buy.
Update:
  I replaced my amp with a Nuprime IDA8 integrated amp.  It sounds great and I love the internal DAC.  Much more compact system now.
They only go to 100W/8ohms.  I am now looking towards efficient speakers to replace my Studio-20s.