I’m also a tube guy at heart and I tend to keep tube gear a lot longer than when I have solid-state electronics. I get bored with SS amps/integrateds after 6-8 months and look to try something different; whereas, whenever I’ve had a tube setup (tube separates or a tube integrated), I’ve held onto it for as long as 5 years without making any changes.
In the late 90’s, I attended this Stereophile Single Ended Symposium in Philadelphia and it was the first time I ever heard SET amps and was completely blown away. It literally was a whose who of industry people and I heard SET amps from Audio Note, Berning, Cary, Fi, Caztech and a few others using 845s, 211s, 300Bs and 2a3s on very efficient horn speakers and concluded while they all sounded incredible and was the b3st thing I’ve ever heard, it was the least expensive and lowest powered 2a3 monos from Fi that sounded best to me.
About 7 years later, I attended another stereo show in Central NJ put on by Vacuum Tube Valley magazine. On that day, I heard her many different setups, solid state Class A, AB, SET, PP, Class D, Class D with a tube preamp, and 15 or so different tube amps ranging from 300Bs, 2a3’s, 45s, 10s, 845s, EL84, EL34s, 6L6s, 6B4Gs, 6550s & KT88s. Prior to that day I never heard a Class D amp or single driver speakers. At the end of the day, my 2 favorite setups was an Italian SET amp that was demoed using 45s,10s, 2a3s, 300Bs and 52s on single driver Laemhorn speakers and an EL84 Dyna mkII reissue on single driver Omega speakers. A close 3rd was a custom Dynaco Stereo 70 using 6B4Gs in PP Triode on Rogers LS3/5as.
So, to the original post, maybe just pick up a couple SS amps of excellent performance at a reasonable price with different power ratings that you can swap in and out to keep it fun. You can run the SS amps in the summer and the tube gear in the winter.
Some reasonable priced Giantkillers are:
(200 wpc) B&K EX442 or EX442 Sonata, PS Audio 200C or 200CX, Perreaux 2150, Aragon 4004
(150 wpc): Tandberg 3002, Moscode 300, VSP Labs TransMos 150, Odyssey Stratos, Nakamichi PA5
(100 wpc & below): Classe Ten, Aragon 2004, Meitner STR50, Robertson 4010, Quad 405-2, PS Audio 100C, Acoustat TNT120.
Have fun and enjoy the journey.