40x30 is a good matrix size for text and not bad for pictures. If you are using the TM1809 strips, that is 33mm between pixels (30 pixels per meter)
I'm working up a set of 1/2" PVC rods, each one having 2 meters (60 pixels) of Flex Strips zip tied down the front.
Ultimate goal will be to make 80 of them. For now, I'm using 16 and set up as a small Mega-tree.
When/If I get 80 of them built, I'll hang them from hooks across a frame in a very nice matrix. To be very flexible, each stick will be stand-alone. That will need a lot of SSCs.