I prefer to have the EnderChest and Input Bus like you described to start, then the DSU on a Storage Bus with high priority. Note, AE will continue to fill any partial inventories before it moves on, so you may have to prime the DSU and then run your drives through a ME I/O Port to get all the cobble where you want it. I do this with a barrel wall of things I accumulate en masse, and it serves me well.
After rereading this I realized everything is exactly how I do it. Enderchest to import bus (then later a tesserac feeding the enderchest). That way both tesseracs and enderchests can be used to feed ME.