Welcome soundhd! Wow, 6 systems. I have JBL and Bryston in my collection too. L20 (like your 4406), L19 (like your 4301) and 4430. Aren't the 4301 something else? My L19 are what I listen to most. Had a few 4Bs in the 80s, but now nothing more powerful than the 3B for me.
Regarding a preamp, don't dismiss a used SP1.7. It's easily the best value out there. I have and use it exclusively in 2 channel analog mode.
Happy listening.