I've been on the same search myself for a couple of years...but I want warmth AND detail, and finding the right mix hasn't been all that easy. I would say ARC's are generally out, except for older ones, like the SP8. Years ago I had CJ gear, and I recently bought an old PV5, which is having some work done on it, but the buzz on it is that it's about as warm as you get...maybe too warm. I tried Cary gear, and would not recommend the SLP98--the one I had was wired with silver wire and was not warm. (I hate the sound of silver wire, but I guarantee that some people will say I'm crazy if I didn't think the SLP98 wasn't the warmest thing imaginable.) The SLP2002 was not bad, but in the end, didn't really quite get where I wanted. Same with a couple of Joule preamps (in fact, the LAP 150 is in many respects wonderful, but just a bit too much fizz at the top.) I kept hearing that BAT gear was "dark" so I thought that might work, and now use a BAT VK31, NOT the SE version. (The SE versions have the Russian "super tubes" in them, and seem a bit cold to me.) I put Amperex Bugle Boy tubes in it, and it's pretty darn nice.
Good luck, and tell us what you end up with.
Good luck, and tell us what you end up with.