Tubes for Canary 330 mkII mono's

In all likelyhood you will be able to use 6SN7GT, -GTAs, and -GTBs.
The first couple I would recommend rolling are Sylvania GTB and RCA GTB (not coin base). If you get the green light on GTs they are generally better. Once you can tell us what sonic attribute you most desire then I can recommend others.
I use Sylvania Ws which predate the GTs even and were made for a good period of time. They sell at a premium but are almost always available if you can stand the risk of eBay buying.
I have a pretty large collection of other 6SN7s and have tried virtually all I own. The Sylvania GTs you want to get, if permitted, are either the bottom getter VT231 2 rivet hole or 3 rivet hole plate "bad Boy" or the top getter early GTs or Ws with opposed T plate 3 hole Chrome Dome type. The chrome dome have heavy getter flashing running approx 1/3 to 2/3 down the tube. I just bought some more GTAs with that same construction, they are a worthy sleeper. If you buy the Sylvania GTB get the ones with the green printing on the black base.
There are tons of variants as you will discover. I would avoid the nearest Euro equivalents ECC32 ECC33 CV181 CV1988 until you know if they are in compliance with your amp. I don't know much about the KR or the rectifier so someone else will have to help you with that.

No I am not using Canary's, that's why I was cautioning you about the GTB vs the GT's and GTA's. If Authur Salvatore can use WGTs then you can use almost any type you want.
Coin base is a thin black plastic base found on recent/late 70's GTBs. It resembles a poker chip or about the thickness of a coin.
The concert hall sound stage you want may be found if you use the Sylvania GTs. I would guess that you'll end up with W's after doing some experimenting or"rolling" which is the only way to know if you have nailed the sonic you want. If you want to try the WGTs (which have T shaped opposing 3 hole black plates architecture and a brown base with green lettering) be careful not to buy the WGTA which is generally thought to be somewhat inferior. They have very good imaging, are very detailed and are fast.