Considering the stocking plan the skimmers would be rated as follows-
9415- 120 gallons
9430- 240 gallons
9430 DC 278 gallons
Either the 9430 or 9430 DC will work and which to choose largely depends on personal preference, DC pumps have more parts and won't last as long as the electronics have a finite life span, usually around 7-8 years. On the other hand they are much easier to tune and more powerful.