Where do I start-amp or speakers ?

@michaeljbrown You mentioned early on that you had Altec horns with tubes, so the Thiels are not the only speakers you owned ( lived with ). You say the horn system sounded pretty good, but, what I gather from your information, the best sound you achieved ( enjoyed ) was the Krell and Thiel combo ( specifically the smaller Thiels of the 3 ). You know the music you enjoy listening to, and have some idea of the listening levels you enjoy. If this is correct, then you have a good idea of the sound you like. Your room size is quite smaller ( different ), with much higher ceilings. Your speaker / room / listening position will likely be quite different than the prior room, so I would concentrate on speakers first, and compliment them with the amp ( imo / ime ). To get started, obtain a 2nd hand ss amp with some power and current ( another Krell, but I am sure you can get some recommendations here ), which will open you up to any / most speakers, and once you find the speakers, determine if the amp is a keeper. And of course, pay attention to room acoustics and the incoming power from your breaker. Enjoy the journey, again !

No question... Speakers First !   

Have fun on your system rebuild adventure ... 

This is all just opinion, so everyone will have a different answer. I agree with speakers first. I would pick the speakers that best fit your room size, listening taste (the type of music you listen to and the volume you listen at), and the aesthetics you are looking for. Then look for the proper amplification. You could buy a great 35 Watt/Channel tube amp but it won't do you much good if you later decide you want a big pair of planars or electrostats. Likewise you could buy a great 200 Watt/Channel Solid State amp but it won't be a good match if you later decide you want high efficiency speakers. Again just opinion.

The Krell/Thiel combo is very nice. I had the Krell FPB-300 paired with the Thiel CS3.7 speakers and it sounded ideal to me. This is also an affordable combo, as you can get this pairing on the resale market for $8K - $9K. 

My two cents is that the amp / speaker combo should really be seen as one unit.  In fact to take it to its conclusion then go for Active Speakers.  You lose some flexibility, (not good) but you gain perfect integration (good) and you lose speaker cables (good).  Still, to answer the OP: I think the consensus is that speakers have more influence on the sound than other components so I would give them priority.