In my Cayin amp I use the Sovtek KT88 and the JJ 803 with excellent results. I find both as described in the tubestore description. I've used the Sovteks for many years and have found them very reliable. The JJ's are new to me.
If you want a fuller bass and something a bit more forward in the (upper)mid range the new production Tong Sols are quite good as well.
Can't help you on the AT's.
FWIW I think you might find the Sovtek 12ax7's clean and clear in tone but not particulariy warm. The JJ KT88 is supposed to sound good but may have QC issues. I'm not partial to any of the EH tubes, except for their 6CG7's, in general. I've tried. :-)
Hope that helps a bit.
If you want a fuller bass and something a bit more forward in the (upper)mid range the new production Tong Sols are quite good as well.
Can't help you on the AT's.
FWIW I think you might find the Sovtek 12ax7's clean and clear in tone but not particulariy warm. The JJ KT88 is supposed to sound good but may have QC issues. I'm not partial to any of the EH tubes, except for their 6CG7's, in general. I've tried. :-)
Hope that helps a bit.