Fish Choice & Plans [BobbyB] - Advice Please

Glad that previous advice has been helpful for your fishless cycling.

Your proposed fish are a mix of hard water (guppies, platies) and soft water (neon tetra). Looking back at your previous posts, your have water hardness of 14 German degrees / dH which Sue has helpfully converted to 242 ppm. Unfortunately, according to the Seriously Fish profiles, this would be too hard for neon tetras which require a hardness range of 18-215 ppm. However, the guppies and platies should be fine - guppies require 143-536 ppm and platies 10-30 dH.

An alternative to the neon tetras would be x-ray tetras which can tolerate a wider hardness range - 2-20 dH. If these aren't of interest, then there are still plenty of other fish options but that's the first which springs to mind.

Once a fishless cycle is complete, it should be fine to add all your proposed fish at once.

As for your other guppy-related questions, you might find this http://www.seriouslyfish.com/species/poecilia-reticulata/ helpful as a starter-for-ten, if you haven't seen it already.

All colour forms and patterns of guppy are the same species. Like chihuahuas, labradors and great danes are all the same species.
You may see fish described as endler guppies - these are hybrids of endlers and guppies. Most, if not all, of the fish sold as endlers in shops are really hybrids.

Here are a couple of links to give to some ideas
http://wetwebmedia.com/fwsubwebindex/fwhardness.htm
http://www.wetwebmedia.com/FWSubWebIndex/HardWatrCommTkStkMonks.htm

Check out the actual hardness requirements of fish on Seriously Fish http://www.seriouslyfish.com/knowledge-base/