I agree 100% with what you're plan (tube amp, SS pre) to get a warm sound. I say to keep it simple, get the tube amp before you do anything. It should make a huge difference! Then start changing other items. But remember that you're sound is only as good as the weakest link, and you're weakest link could as easily be your source component as it could be your speakers.
The only tube amp that you can count on to deliver is any Audio Research amp in the last 15-20 years. If you use one of those and the sound doesn't come into focus, then it's your speakers or your source. (I'm not saying that other tube amps are not as good as ARC, I'm just saying that ARC is a veritable sure thing).
I haven't found cables to make that big of difference with a good tube amp, though, of course, quality cables should certainly be used. But, I do not agree with using cables to EQ your system.
The only tube amp that you can count on to deliver is any Audio Research amp in the last 15-20 years. If you use one of those and the sound doesn't come into focus, then it's your speakers or your source. (I'm not saying that other tube amps are not as good as ARC, I'm just saying that ARC is a veritable sure thing).
I haven't found cables to make that big of difference with a good tube amp, though, of course, quality cables should certainly be used. But, I do not agree with using cables to EQ your system.