Mike I have an Audio Innovations L2 valve pre that may be of interest.
I used it with Audio innovations valve power amps as well as with solid state amps and it always sounds great. Had it to a few Bake offs and it always went down well.
Modified to the max by Definitive Audio, it really is a great bit of kit. Here is an old sale thread of mine for it.
http://theartofsound.net/forum/showt...-valve-pre-amp
as you know, I come up regularly, and will be up again next month. Happy to bring it to you, for you to try out with your power amp.