Auditioning a Tube Amp

My current main setup are Odyssey Stratos Monos, Thiel CS3.5, Denon PRA-1500, and Oppo DV-981HD. I'm actually very satisifed with what I'm getting out of this system. I'm thinking of a low powered (and cost) tube amp for a secondary system. I understand that I will need a higher efficiency speaker. I've had good results with a Klipsch KG-2 and a 7 watt (8 ohm) TA2024 based amp, but if I need to get some better higher efficiency speakers, so be it. Maybe the subject of another post. I also have a number of lower efficiency classics laying around ADS L810, Dynaco A-35, Spica TC-50, and Energy Pro 22 among others.

I've been listening alot to Knopfler's Kill To Get Crimson lately, I'll bring that along for the vocals and maybe some Acoustic Alchemy. The Baby is noted for being dead quiet, but what if there is just a hint of buzz? A bit is acceptable for SS, is it not for tubes? I think I'm going to pick this one up for under $300, so I can splurge a bit for some new tubes or a checkup by Sophia if necessary, as I'm in the DC area. The owner has put in Western Electric tubes and seems very knowledgeable, probably an A-goner himself.

What about the tubes themselves, is there something that can be discerned from how bright they are or
aren't, how they light up or dim on power disconnect? I can compare them to each other, but have no real feel for what is normal.

I picked the Baby up yesterday. It is, in fact, dead quiet and in nice shape. I've run a few pairs of speakers through, knowing they are not, on paper at least, good matches, but with nothing to lose. Klipsch KG-2, Energy Pro 22, and Spica TC-50. None very satisfying. I thought the KG-2 might have been a good match, but no dice. I do have some older Dynaco's, the A-25 and A-35, how would these fair? The only higher efficiency set I have are an Infinity P-FR, but these are going to need some work. I could also go the DIY route and get some Fostex 206 or 207 drivers for $200 or so the pair. The previous owner had Sequerra Mets on it, I've got some feelers out already for a pair of those. Anyway, any ideas in something easy to get and $300 or less for the pair (used, definitely). I'm using a DVD-A player I've had good results with on my main rig, I don't think the source is the issue.