AquaC is coming out with a shorter version of the Remora, to fit on nano tanks. Remoras are pretty good skimmers and aren't hard to get them to produce foam.
As far as the fission skimmers, just about everything that I hear about them is that they are junk.
IIRC, ATR and Aquarium Arts have pretty good pricing on the tanks themselves, although I think ATR has a little better pricing.
You can also check out Pets Inc., the last time I was in there, they had some good prices on nanos as well.