IMO stereo pairs of the REL 212se and 2x stereo REL 812se’s. The 812’s are stackable. I would also consider a stereo pair of the Rel 25.
The 212 and 812 with the smaller drivers would probably be a bit more nimble but the 25 would blend better with larger mains to produce a bigger soundstage.
You could also do 6x REL 812se and be about the same price point as your single Gotha. I’d have to think that 2 REL 812 se x3 stacks are going to be superior to your single Gotham.
GLHF!
The 212 and 812 with the smaller drivers would probably be a bit more nimble but the 25 would blend better with larger mains to produce a bigger soundstage.
You could also do 6x REL 812se and be about the same price point as your single Gotha. I’d have to think that 2 REL 812 se x3 stacks are going to be superior to your single Gotham.
GLHF!