Rip's fly is something like I had in mind!
I generally use larger hooks than most folks, size 8 to 4. I feel I get less swallowed flies & gut hooked fish. But, I think many would use 12 to 8 for Bluegill's unless they're exceptionally large.
I caught some in Florida once that were 12 to 13 inches long, and they took a marabou streamer tied on a size 4 hook. I was looking for bass, but Bluegills that large were fine with me!