I currently have two Mesa 2x12s (which are a similar shape to the 1936 cabs) and that works for me over my previous set up of a Marshall 1960AV.
I used to have a 1936 and did like it but felt that I needed a 4x12 (and an angled one) for gigging as you can hear it easier on stage.
I have heard both cabs 1936 and 1966 and out of the two I would go for the 1966 with out changing the speakers as I should be able to hear myself better.
If I was changing the speakers to Celestion V30s then I would also go for the angled 2x12s.
In terms of tone or punch I couldnt really discern much difference between the 1936 and 1966 BUT I have never heard the two side by side.
but as I say the angled 2x12 might be more apparent because of the angled speaker.
Ultimately it is up to you of course
ps anything else you want to know about Marshall just ask