Looking to upgrade pre amp and looking for suggestions

Current system includes a BAT VK 30 connected via balanced cables to two VK60 mono block amplifiers.
Speakers are Sonus Fabor Electa Amators and two Rel Stadium 2 subwoofers. Front end of Sota Cosmos 4
SME 5 and Shelter  cartridge. Getting a new Herron VTPS-2 phono pre amp.  Marantz SA 14 Cd player.
Considering used pre amps like a BAT 32SE, Bat 51SE, Audio Research LS17SE, Audio Research LS 27, Audio Research Reference 3, Pass XP 20, and Ayre K-5XE.
The BAT 51se would be a HUGE step up! 
I think you'd be blown away by the improvement. 

Good luck 
I would think that it would depend on what you are looking for sonically.

Of those that you mention, I've owned the BAT VK-51SE and the ARC Ref 3. I've also had the VK-32SE in my system for an extended audition.

The BAT VK-51SE and the ARC Ref 3 are both very good preamps, but very different sounding. The BAT being more powerful and dynamic, possibly the best bass of any preamp I've heard. The ARC Ref 3 offers higher resolution and a more extended top end with more detail.
I didn't care for the VK-32SE, it had more midrange bloom and sweetness than the 51SE, but at the expense of dynamics and power.

Another tube unit you may consider is and Atma-Sphere MP3 or MP1.

As for SS, the only preamp that would interest me is a Klyne 7 series.