Hi Ron,
The cardinals and neons sound fine. The cave fish you are talking about is a pleco. Make sure you get a dwarf pleco, like a bristlenose or a clown pleco which grow to about 4" long, not a Common Pleco that can grow to 2.5 feet long. You'd need a bit of bogwood for a pleco to chew and a cave as you rightly said.
If you're going for gouramis, have a look at pearl gouramis as they are easier and gentler than dwarf gouramis. Don't be put off by their dull colours in the LFS - some bloodworms and loving care and they become beautifully coloured fish with bright orange faces. They will set off the upper levels of your tank nicely.
If you are cycling with fish please be aware that the process may take 8-10 weeks and most of the fish you want will not cope well with an un-cycled tank. It could also be a lot of work as it won't be very good if the goldfish die on you (dead fish can't cycle a tank). If you tried fishless techniques, OTOH, you could probably get that tank up and running in a couple of weeks.