No other speaker can mimic the Proac's character.
If you like them, you better choose among their family.
They favor Cardas speaker cables & valves (or Goldmund)!
So, you are allready in their field.
Congratulations for your amp. choice (only Lamm ML2 compares)!
I advise you to keep MA-2 even if you don't need it's power for now. Don't let it go, as it permits you to choose a wide range of speakers for future upgrades maybe in a bigger room.
Sorry I can't help you for Tablette Ref 8 Sig Vs 1SC dillema.
I owned the 5, 4, D38, D28. I love the Proac sound & I feel that it is impossible for someone to like both Proacs & something like Guarneri Hommage (I owned too). It is an analogy like between VDH Colibri & Koetsu Onyx. Strong characters indeed & personal preferances are rulling here.
If you adore the one, you are strongly dislike the other.
Something incredibly unique is the Transmission Audio M1i.
I wish you to give it a try. It is an unforgettable experience that makes any comparison a joke! (for my priorities of course).
I'm happy for your choises. Bravo!