First off I have to say that I have never heard any of these myself, but will comment on others feedback I have read, so take this with that in mind.
The Woo Wee is a very good option to drive Stax. I know of a quite a few people that are doing this and are very happy.
The Lambda Pro should sound very similar to my lambdas that you heard, and driving them on a good speaker amp will most assuredly make them sound better than my lambdas off the toppings T32 I use.
Of the two the SRM-1 lambda pro deal looks like a very good deal IF it all works...
The Woo Wee deal looks a little high in price to me, again if there is no issue with the lambdas or the woo.
But you know haggling the price down is the way to go on both...
My preference would be to get the WOO WEE combo at a lower price or new...$499 for the WEE new ($300 on audiogon), lambda pro - under $300,
Edited by bearFNF - 10/27/13 at 2:40pm