Once the Algae is under control a 30 gal tank might be best with only 2 SAEs.
As your fish grow the CAE will be less interested in the Algae and may start to get nasty with other fish. Don't be surprised if you find a jumper or two. The SAEs will get a aggressive with each other.
I had two about 1.5" when I got them. Around 2.5 " they started to fight and eventually one jumped out. I have the one 4" now 6mos. later in a 40gl. I would not add a 2nd one now. when he gets around 5" I'll trade him in to the LFS and get another small 1" size SAE and start again.