Which tubes? My amp can except El34, 6L6, KT88, an

I am a fan of all four tubes you listed. My current favorite has to be the 6L6 though. Seeing how you'll need a dozen, they will probably be the cheapest of the four. They are not the best at low end, but your Vandy's amps will take care of that. The midrange is to die for. Female vocals are just awesome. Stunningly awesome. All the midrange magic of the EL34, but sweeter (to me the EL34 sounds a lot like a 6L6, only much drier). They produce a great 3D soundstage. They do pretty well with rock, hip hop and techno as well. I've had best results from Russian 6N3C (a variant of the 6L6), they are fantastic. The Svetlana 6L6 is pretty good. You might avoid the JJ Tesla 6L6, as it has a compressed sound. I liked it at first, but quickly tired of it. Too much loss of micro and macro dynamics. As Maxgain alluded to, it's very much a personal choice. Good luck and happy tube-rolling!

ps - I'll take the rocky road in a regular cone

Maxgain, that's very interesting about how the Vandy's amps get their signal. Perhaps the 6L6 wouldn't be the best in this situation. They are cheap to experiment with though. I found the Golden Dragon KT88 to have as much bottom end as a Sovtek 6550. The Sovtek seemed a little compressed. But the Svetlana 6550 is great. Very linear. Better slam factor than the KT88.

Kana's suggestion of the KT90 is a good one too, if you can run them. Make sure you get the type 3, matched and tested. They have some quality/reliability issues, but the ones I got from Upscale Audio were very nice. They took a long, long time to burn in and settle down, perhaps 300 hours or so. But in the end, they offered a solid state like low end, and great linearity. In a Sonic Frontiers SFS-40, they outperformed a pair of bridged Adcom GFA-555's in the low end!