Zd542, "...the other way around...".
Glaaspak, It depends on you and your system. The S series amps run the first 20% in Class A into 8 Ohms, but while the power doubles down into lower impedances, the class A % halves accordingly. The Class A/AB S series is more forward and vivid, the Class A series is more relaxed and distant.
While I am very familiar with the Meadowlark Kestral hot rods, I'm not familiar with your Meadowlarks. It might just come down to which presentation you prefer and how much power you need. As you can see from my above description, sometimes the more powerful S series might have enough Class A sound with more reserve power. On the other hand if your room isn't too big, or you don't listen to music with lifelike dynamic contrasts, the less powerful Class A SA series might be preferable. The SA series do seem to cost significantly more though. You might end up lacking enough power at your budget to afford the SA series sound? If you crave some of the Class A sound on a more restricted budget; you might be, (somewhat ironically) somewhat compensated by buying more power than you need in a more affordable S series amp. The later e series amps have balanced inputs, and some have dual trannies. With your c-j pre I don't think you'll find that important.
BTW, Jon is a pleasure to do business with, and the Thresholds were really built well in their day. IMHO, While there might be some other amps in your price range that might compete, there aren't many. My experience with the newer class D amps have been inconsistent, but to be truthful very limited.