If you'd care to step up by using mono blocks that step will prove itself a noteworthy one indeed.
For a SET like sound with some horsepower, the Thor PA 30 or later monos are incredible.... Made exceptionally well, but no maker support. Can be had now for a song though, comparitively speaking vs. orig costs. I've heard these amps and fell in love at first listen.
The next step up performance wise would be their bigger bros, the PA 60's. Ultralinear Oh my gosh performance.
you've got to look into Gary Dodds 120 MK II monos, also running in ultralinear. I own these amps with the cap upgrades and enjoy them immensely. they hold bias well, are extremely quiet and will drive most speakers. Very nice and the pair used goes from what I've seen as little as $1900, to $2500, with the cap upgrades.... NOW Gary is putting out a pair of them rated at still more power... 150 wpc... with more improvements.
Retubing costs for the above is cheap too as those costs go... 4 EL34s per amp, 3 mini tubes or so per unit as well... under $300 for quality tubes overall costs total.
Any of these will satisfy your goals... and then some perhaps.