Hi John... The Coincidents are the MK-II version upgraded with Jupiter Premium Copper Foil caps. I did an A/B with the Mk-III version a year ago and frankly liked the MK-II w/ Jupiters better. As for 300B tubes I have Western Electric, PSvane, etc. but the WEs are easily the best. As for the other tubes I have a bunch of NOS 5U4 ect. I'm actually on vacation this week and next but if you have interest in the amps let me know as I'm going to list as soon as I get back.
Som for Dennis's PSE 300B it does run hot. Personally I think the chassis could be made a bit larger to enable better cooling. But with four 300Bs and a number of large resisters needed for tube not transformer coupling I guess hot is the logical outcome.
Best regards,
Mark