Instead of replacing the amps, consider trying a different output tube. I have Wright Mono 10 amps, which are Push-Pull 2A3 amps, and am really enjoying them especially after switching to Sophia Electric Princess 300B 2.5v tubes.
http://www.sophiaelectric.com/pages/se/princess_300b_25v.htm
They are designed as 2A3 replacements, and are definitely lusher than the 2A3's and in my opinion, bring the amps to another level. They are expensive though, at over $300 for the pair, and take a VERY long time to break in fully (over 300 hours), but are really very good.
http://www.sophiaelectric.com/pages/se/princess_300b_25v.htm
They are designed as 2A3 replacements, and are definitely lusher than the 2A3's and in my opinion, bring the amps to another level. They are expensive though, at over $300 for the pair, and take a VERY long time to break in fully (over 300 hours), but are really very good.