Tube Pre for Parasound A-21 or Jeff Rowland M201

I'm looking at going to a Tube preamp to drive my solid state amps, currently I'm looking at either a VTL 5.5 Signature Series or the VTL 2.5 preamps.

The tube preamp will drive either my Parasound A-21 or a pair of Jeff Rowland 201 mono blocks, speakers are Sonus Faber Luito Towers, these are not bi-ampable. I won't be bi-amping just use one amp or the other.

Has anyone experience with these VTL pre's running either of my amps, which preamp is recommended.. I don't mind having to roll tubes if need be.. thanks.
The 2.5 is a great preamp. It has a very lively and dynamic sound. It will definitely work ok with the Parasound, but with the Rowland you may want to go with something that is balanced and a bit cleaner sounding overall. An Aesthetix Calypso should sound great with both amps.