Hi!
Can I add a few fish to Spanishguy's stocking list? I love stocking other people's tanks (my platy is busy stocking my tank so I don't get to do that).
What fish you can start with depends on how you do your cycling. Cycling is the process of encouraging enough friendly bacteria to grow to deal with the fish's waste. You can either cycle with fish or fishless. Read up the pinned topics above!
If you cycle with fish, only a few fish are hardy enough to cope with the cycling process, so you would have to add a few of those first and then add your other fish very gradually after the readings of ammonia and nitrite had disappeared.
If you cycle fishless (add ammonia from bottle every day until readings for ammonia and nitrites disappear), once the process is finished you can then add any fish that are not specifically stated to need a mature tank. Hardy corys, many tetras, the common livebearers etc, you get quite a wide choice.
As Spanishguy said, most of the fish you mentioned are not terribly hardy and some perhaps best avoided until you have more experience. But there is plenty to choose from.
Corys. Bronzes are a very good choice. The albinos you see in the shop are usually a colour morph of bronze. The peppered corys are also hardy and easy to keep. I've got those and they're gorgeous. Corys like to be in schools, have a hiding place and to be fed catfish pellets or tablets, with vegetable and bloodworm now and then.
Then again the bristlenose would be a nice alternative. They have the advantage of eating algae which corys do not do.
Cardinal tetras. Are supposed to be slightly hardier than neons, but that is probably not saying a lot. I'd check out other tetras if I were you, have a poke round the shops and then post in the characin forum to find out the hardiness of any species that takes your fancy. Spanishguy mentioned WCM's, they are a lovely fish, like slightly cooler water, so may not go well with gouramis, but fine with many corys.
Instead of tetras you might want to look at rasboras. Often slightly hardier, nice schooling behaviour.
With a nice-sized tank like that, you might want to consider a shoal of danios instead. Very active, hardy fish.
Rams/Gouramis. What you're looking for here is a centrepiece fish.
Well, probably better to wait with the rams. Lots of people have problems with them. And as Spanishguy says, for gouramis you'll be better off with a bigger hardier kind than the dwarf, which is very inbred and very sensitive to parasites etc these days. Two-spot or maybe lace/pearl gouramis, a trio (2 females, 1 male) should work well. Though they may find danios a bit too active. With gouramis you need to make sure you are not keeping any fin-nipping fish. Rasboras should be fine.
It is unlikely that you will have any breeding problems in the sense of being overrun; gouramis seldom breed in a community tank and if they do the babies are unlikely to survive. The same goes for most egglayers, though bristlenoses have been known to bring up babies quite happily in a community.
Then there are livebearers. Platys are lovely little fish, colourful and sociable, or if you wanted a bit more action you could go for swordtails. In either case, unless you are keeping one sex only, make sure you have a ratio of at least 2 females to every male, as livebearer males are extremely highly sexed and never listen to any excuses about headaches...
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A lone female in a tank of males would soon die from sexual exhaustion. Livebearers do breed without encouragement; it is enough for a female to have been in contact with a male once, and she can produce up to 7 batches of fry.
Whatever you do, be careful not to overstock, particularly with livebearers as they will see to that themselves.... Never, ever go by what you see in a shop, they have to keep their tanks grossly overstocked to earn a living. The fish cope because of massive filtration (totally different kind from a home tank) and from the fact that they are only in there for a few days. It's like being crammed on a busy bus; you can survive for a few hours, but it's not much of a quality of life.
Good luck and enjoy yourself!
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