Completing and old system: suggestions for class A amplifier

I’m finally going to complete my old system, which I kept sleeping for several years.
I’m looking for advices on amplifier.Actually I have a Threshold Fet Ten preamp, a Bryston 4BNRB, while a couple of Boston Lynfield 300L is arriving.
I feel all will be well balanced, as the Bryston has the power for driving the 300L.

But:
- I always dreamed to couple the Fet Ten with a Threshold (Pass) amplifier.
- I’m very curious to hear a class A amplifier in this chain.

As my listening room is small (16 squared meters), I feel Threshold SA/3 may be the solution, but I see a pletora of new Pass models, Pass DIY models (Aleph), and also a lot of new brands.

What do you advice for driving at the best these speakers?
Does the SA/3 still worth, or would it be better to move (considering second hand prices) to different models?
Would 50+50W be enought or should I keep my Bryston (or a more recent one)?
Thanks for anyone willing to help me.

Tonino

P.S. I live in Italy, so please mention models available worldwide.