“Quality watts” is a catch-phrase, in that any manufacturer will tell you their amps provide quality watts. It is simply another way of saying expensive amps often sound better than inexpensive amps and, given their speakers, room, music, and listening habits, some listeners prefer an expensive amp that provides less power to a more powerful but less expensive amp. Of course, if your budget allows, figure out your power needs and then buy the amp that meets those power requirements while sounding best to you.
Listen for yourself and decide on the type of amp that sounds best to you. Decide for sure that you plan to stick with your current speakers. Tube watts, and Class A watts can be expensive. A SS amp, or amps, will be less expensive to provide the amount of power you need for your medium efficiency 89dB speakers. Consider the type of music you listen to, and the volume you listen at. Do you like to occasionally rock out and, if so, do you want enough power and headroom for a realistic portrayal of the crescendos? Do some research on sound pressures for your chosen music and listening habits and then use something like this calculator to verify how much power you need. I would guess at least 100 wpc with 200 wpc being optimal, if you want the ability to occasionally crank it up.
Try Class A amps if you must but IME of owning several, they are generally over-hyped for the sound, the inefficiency and heat, and the cost per watt. I would look for a well-built, well-regarded, class A-B amp that provides the power you need. Go listen to some amps, if not at a dealer, then in your friend’s systems, or at an audio show. Or, if you must, read the reviews, buy something, take your chances, and sell it if you don’t like it. You won’t be the first or last to do that, and neither was I but, relying on reviews and feedback from others can be a longer road to satisfaction than hearing stuff for yourself before buying.