Tube amp location

I've got a question for you tube guys. I'd like to add a couple of mono tube amps to my combo HT/audio rig. Problem is I have my equipment in an entertainment center which has glass doors on the front, so heat would probably be a problem.

The glass doors are not sealed and have about a 1/4" opening aroung the edge. The back of the entertainment center is fiber board which I cut out around all my equipmet for ventilation and access to wiring. I can easily get 6-8" clearance on top of the components, but only have 20" side to side.

I'm thinking this is not enough ventilation for tubes and I don't have space to put them on floor. Not to mention my wife would throw a fit. So my only other option is on top the of the speakers.

I have Klipsch Cornwall III's so I have a fairly large area to set the amps on, but I'm worried the vibration from the speakers would adversly effect the amplifiers/sound.

What do you guys think? Stick with solid state?

Thanks.