Suggestions for medium priced Power amp and Pre-Amp Combo's

You’re likely better off looking for a nice used integrated amp. I don’t think you will get as good with separate preamp/power scenarios. If you can stretch youre budget to $2398, I would recommend the Kinki Studio EX-M1. It’s quite powerful at 215 watts per channel and has extraordinary sound quality for the money. The internal op amps are socketed, so you can always upgrade the op amps in the future if you want increased sound quality.

There are a couple Hegels for under $2k, but they are somewhat low power. Hegel H95 on usaudiomart for $1750 but only 60 watts per channel. A Hegel H120 on ebay for auction starting at $1975 but only 75 watts per channel.

ADD: sorry, I didn't catch your "tube" requirement.

First, what model loudspeakers do you have. Second, tube amps are more costly than solid state. Your budget really isn't enough for an amp driving Magnepans. 

Parasound Hint integrated used should be available for under 2K. John Curl design worked magic with my Maggie 1.7 speakers.
Good luck

As mentioned Parasound and also Odyssey Audio come to mind as reasonable options that are on the warmer side of the spectrum. Add a tube preamp. For new you could look at a standard Odyssey Stratos for $1,400 or a used Parasound A21 for probably around the same price if you are patient. Always a few for sale so they may be negotiable. 

Add a new Schiit Saga+ tube preamp for $400 and you are rockin or spend a few hundred more for a Schiit Freya. I have to confess I have not personally heard any Schiits but I am considering ordering the Freya +. They seem to get rave reviews at their price points. 

As others mentioned an integrated would be a good option as well. 

Agreed in your price range probably not going get full tube amp that is going to do any justice to Maggie type speaker. 

The Odyssey Audio amps are actually not warm at all.  They are very high resolution and fast responding.  The Odyssey Khartago base model at $995 would likely be a very excellent option (just keep in mind that it's a manual turn on and does not have a remote trigger input).

The Parasound amps are definitely voiced very slightly on the warm side.  Though I would describe the high frequencies as dry sounding as well as being softened/rolled off.

Schiit Freya is likely an excellent budget tube preamp suggestion.  If you did this, I would go with the Odyssey Khartago amp.  It sets you up for tube sound and you can try different tubes in the future for tuning your sonic signature.

I had a Stratos + in the early 2000s then an Extreme a couple years ago. I found that you could set the bias higher for a slightly “warmer” sound and lower for a little bit leaner and faster sound. I ran mine on the upper end of the high safe recommendation. 
Last one I had I blew the damn thing up doing the bias! Shorted out something with the meter. 

I also suggest an integrated amp. Explore NAD...

Nad New model is exceptional

Tubes for $2k?
Schiit Freya+ for Preamp.
Maybe a rebuilt Dynaco ST-70 for an amplifier?
Right around 2kish.

I missed the tube requirement...Rogue could be an option.  I have been impressed with the models I have heard and they have some features that appeal me as a tube novice.