that's sounds like fun. As for Pioneer and Marantz, not sure if they are doing that anymore, unless you are talking used amplifier. Seems these are the new players: http://www.stereophile.com/category/tube-power-amp-reviews
I grew up listening to 70s receivers and I remember those sounds. If I get lucky someday I'll get a Pioneer or Marantz from that heyday. As for now I'm looking to put together a system in the midrange and possibly later build my own speakers. I listened to 70s and 80s rock and now I have the opportunity to enjoy retirement jamming to that good old rock and roll.