Ttrhp, the 300SEs will sound great with your Unos - I am using those amps with my Duo 3.2s. Be sure to try Sophia mesh plate 300Bs, better than the Western Electrrics in my system.
Have not heard the 2A3 w/the Duos, so can't say the 300B amps will be "better", but the extra power may come in handy.