would this tank work
 

2 german rams
10 neon tetras
8-10 whiteskirt tetras
5 upside down catfish

would a temp of 79 work with these fish
tank size is a 55 gallon long

I do not know of anyone who has kept the German blue rams for long,, in temperatures less than 82 degree's F, which would be too warm for the neons and whiteskirts.
Bolivian ram, doesn't require this warm of temperature and is accepting of wider range of water parameter's .
Cardinal tetra's would enjoy the warm soft water that Rams need and would in my view be better choice than the Neon's who are increasingly becoming less and less hardy.

Agree. Also, be cautious of the whiteskirt tetra; this is a variant of the Black Widow Tetra (aka Black Skirt T) and can be a fin nipper so tankmates need to be carefully chosen. A better alternative would be one of the quieter Rosy clade species in Hyphessobrycon (Rosy Tetra, Roberts Tetra, Black Phantom, etc) of the delightful Garnet Tetra.

Byron.

You could probably have a more peaceful arrangement by replacing the white skirts with something like black phantoms. My black widow tetras don't bother anything outside of their group but, there's always some kind of nipping going on between them.