I agree, if you’re replacing the amp and speakers at the same time, most people prefer to select or determine their top 1-3 speakers before purchasing an amp. However, if you’re interested in a tube amp like CJ or MAC, it may influence your speaker selection to some degree. Specifically, how much power is needed to drive the speakers and possibly that “tube” sound impacting the sonic characteristics of the speakers. Just keep this in mind when you audition speakers.
Since you mentioned CJ, a used Classic 60SE or new Classic 62SE is a great place to start. They offer that classic CJ sound at a lower price point. If you need more power, you could consider the 100 watt Classic. Hope this helps. Enjoy the journey.