Class A SS vs. Class A/B SS

I am looking for a new amp/integrated for my Adagios (89db), I currently run KT88/6sn7 tube monos (50w), i want to buy a SS setup for when I want to just fire up an play (my vintage tubes take a while to warm up), I am torn between a high quality A/B design (eg. Bryston 4bsst, Pass, even Class D Bel Canto, W4S or MF integrated) or a true Class A amp like the 30w Pass 30.5 or a Class A Luxman or Accuphase etc. I am kinda leaning toward integrated for the convenience. I listen to primarily vinyl. Please help I know much less wattage is required for class A but how much is enough?