Don't get a pair - either get a trio of dwarf gouramies (1 male, 2 females) or stick with the single male. Many shops sell them as pairs but you are much better off (and so are the fish) if you can either persuade them to sell you two females and a male (they usually agree to this) or if you buy a single male from elsewhere.
Remember to fishless cycle before adding any fish. None of those you are planning are particularly hardy and most will not survive the cycling process.
Remember to fishless cycle before adding any fish. None of those you are planning are particularly hardy and most will not survive the cycling process.