OK, one more question concerning this setup.

Should I hook the return pump to the sump and split a line off of it to the fuge and then have it gravity drain back into the sump?

If I do that, I would not have to put glass baffles in the 180 at all. I would also only have to get one hole drilled. I like this idea. It would also allow me to use the full 180 gallons for the fuge rather than wasting space worrying about baffles and bubble traps.

I would the build the bubble traps into the 55 gallon tank or have a pretty large sump built.