I've played around with some of these. I have a couple of Magnavox amps - one Stereo EL84 based (9302), and one Stereo 6V6 based (8802). The Maggies are popular and not bad sounding. I also have a pair of Thordarsen mono amps that are 6V6, 6SL7 based - they sound amazing.
These are all easy to work on, and you can find some plug n play if you look.
Here's some pics Vintage amps
These are all easy to work on, and you can find some plug n play if you look.
Here's some pics Vintage amps