Jeff,
I'm not familiar with your amps, but I have tried tons of 12bh7's in amps, and have found sonic differences. You can buy them fairly cheap at ebay, if you want to try many different brands. I have seen some sellers selling a few brands at once. And if you don't need them in matched pairs, you can gobble up lots of tubes cheap! If you have a brand in mind let me know, I can tell you what sonic characteristics the brand had in my experiments.
I'm not familiar with your amps, but I have tried tons of 12bh7's in amps, and have found sonic differences. You can buy them fairly cheap at ebay, if you want to try many different brands. I have seen some sellers selling a few brands at once. And if you don't need them in matched pairs, you can gobble up lots of tubes cheap! If you have a brand in mind let me know, I can tell you what sonic characteristics the brand had in my experiments.