Help getting a Tube Amp

I have a pair of Monitor Audio Studio 6 Loudspeakers 88.5 db 6 ohms min. . I haven't used them for a few years but I would like to get a good tube amp and a sub woofer. My room is 11.5' wide x 17'long, I was thinking of an 845 amp is this enough power?
If an set isn't enough power what is ? I listen to mostly rock and sometimes classical.
I never used a sub woofer so any help with a sub for 2 channel only is appreciated.
Thank you
Check out Atma-Sphere products at the website. They produce excellant bass response so that you may not even need a sub. I use their M-60's, have a large room, and drive a pair of Harmon Kardon Sixty's which are only a bit more sensitive than your Monitor Audio's. They are easy to bias (they may even self bias with the current production models), and replacement tubes are reasonably priced although there are quite a few to replace when needed. My original set of tubes are in their third or fourth year of service (amplifiers) and are still going strong. Contact atma-sphere and they can give you excellant advise regarding your own equipment and application.
I think there is not likely to be any SET that will work with you speakers, I think you need 50-60 watts. I also own Atma-sphere amps and they are great, with the right speaker. Don't know your speaker, but ask Ralph at Atma-spher what he thinks, they are sensitive enough, but like most tube amps, you really want a smooth impedance curve to work best. Atma amps are great though for sure.
Thanks for the info,I'll email Atma-Sphere.
What about a sub ? Any recommendations ?

Amp power is only part of the problem. Unless the amp has a low output impedance (not typical of tube amps), you have a much bigger issue with the impedance curve of the speaker. For a typical tube amp, you want a speaker with a very smooth impedance curve. Speakers today seem to be designed for low output impedance amps (typically solid state). Scan the speaker measurements in the Stereophile archive for examples.

Your room is not huge and for music only, just about any well made sub will work well. I would not consider anything smaller than a 12" driver. Usually, sealed box designs (having better group delay) are considered more suitable for music. You need to decide whether to run your main speakers full range or not. And whether you'll want to apply EQ to the bass.
Mcfarland, Are you still looking for a tube amp to drive your Monitor Audio Studio 6's? I have an 845 amp and would like to tell you about it. Steve