Grass carp won't help with the algae.
I hear you on the aeration/diffuser setups. I don't have one yet, and saving up for one myself.
Your going to want to hang tight on adding LMB and wait for the pros opinions on stocking options. I would think if you stock some LMB, you will want to stock a forage fish at the same time with them. That way when your LMB have eaten all the goldfish they will have some other type of food. If the LMB get to big, it might be tough to get another type of forage fish established at that point.
