Best tube preamp for Quicksilver V4 tube mono's (newest KT150 version)

Just purchased a pair of Quicksilver V4 mono tube amps, the newest KT150 version.  Will be arriving this coming Wednesday.

Single ended
Input impedance is 100 K ohms
Input sensitivity is 1.5 volts

Now need to purchase a nice preamp.  Would like to get the most 'bang for buck' by getting a very nice condition used pre-amp.

On my radar so far is:

EAR 868
Audible Illusions M3b or L3a
Herron VTSP-360

I have had 2 different AI M3a pre-amps in the past, so I am very familiar with Audible Illusions 'sound'... not sure what is the differences between the AI M3b and AI L3a, besides the M3b having  phono stage options and the L3a remote controlled volume?

No experience with Herron or EAR, but from what I have read EAR, if compatible, may be the best performing?

Suggestions greatly appreciated. 

Also would like to hear from other V4 owners.

Get out..Audio Connection without Johnny R is like the Starship Enterprise without Captain Kirk. Cheers Johnny -Don
Yes, the wise old owl was Hart Hutchens that began AC in 1980 we always had a great relationship. 9 years later1989 is when I arrived on the scene with expanded offerings like Audio Research Ayre Aesthetix Audioquest Aurender Belles Bryston CAD HRS Innous Magnepan Proac Rega Rogue Rotel AMG Clear Audio Bowers Wilkins etc and still having fun!
 Cheers JohnnyR