I concur with Akasha (shouldn't be surprising...
) and will go a bit further as I see other issues.
First on the Denison Barbs (
Sahyadria denisonii, though may still be encountered in
Puntius), if you want a group of this barb, consider this as your main fish and you need eight. They are active swimmers, requiring a good oxygen level so a moderate flow from the filter is best, and you could have a sort of stream habitat aquascape with fine gravel, chunks of wood, some rounded river rock. Floating plants, and some substrate-rooted plants. Temperature must be in the low 70's, no higher than 59C/77F but better not this extreme. They are semi-substrate fish, being benthic feeders, so spend most of their time in the lower half or third of the aquarium. Should attain five, maybe six inches, if you get the correct species; another very similar gets much larger and is sometimes not very peaceful.
You certainly do not want the Denisons with angels, for the activity issue and the temperature and the water current.
To the Bosemani rainbows, a group of 6-7 would be fine, if you have moderately hard water. This species is no good in soft and/or acidic water. Also not a good combo with angelfish, for reasons of activity mainly.
As you are seeing, angelfish have specific needs, and it is not always easy finding suitable tankmates. You also do not want two...either one alone, or a group of five-six in your 80g. [Unless you have a bonded mated pair, but that will have other issues.] Angelfish are shoaling fish that establish an hierarchy within the group, and they will continually assert their independence amongst themselves which is fine provided the group is five or more; fewer and it is almost a certainty that one or two will be picked on and this can very quickly cause serious stress and imminent death. There is another current thread with angelfish troubles from a dominant male. It is very common, as it is the fish's inherent nature.
The rainbows and some colourful livebearers (platy, perhaps swordtail) but stay with males only or the tank will quickly become over-run with fry. They will not all get eaten if you have several females giving birth every month.
I won't get into first fish now, as I think more selection has to be made to narrow things down.
Byron.