Setting Up 33 Gallon Long

Hello,

I'm in the process of setting up a new tank. Currently I have a 4-inch
ryukin and a 2-inch telescope eye in a 20 gallon long tank. I just
purchased a 33 gallon long tank. The 33 long is 12 inches tall and 48
inches (4 feet) long.

Right now, the 33 gallon is 2/3 filled with water, but I haven't added
anything else to it yet. I will be using a Penguin 330 filter on one end
of the tank and the old Whisper filter transferred from the 20 gallon on
the other end of the 33 long. Last night I put the new Penguin 330 on
the old 20 gallon tank and its running fine. I noticed that it does
produce a lot of current, but the fish seemed intrigued by it, since
they're busy hanging out directly underneath the fast flowing water.

My questions a What is supposed to go into the two media baskets on
the Penguin? Should I fill these baskets with Whisper filter cartridges?

Also, what size heater should I use for a tank that is 12 inches tall
and 4 feet long?

Also, what are your recommendations for a third roomate to add to the 33
long? I was thinking of a ranchu, but I went to the LFS Sunday and the
fish in several of their tanks had ragged fins and white fluffy stuff on
their scales, so I haven't found a suitable roomate for the ryukin and
telescope yet.