I'd also try to get about 3 of each type. If you can find the kind you have, get a few more. Then you can get another type also, if you have the room.
Its said that cories school by sight, but I believe they know the difference in the types. I have 2 kinds of spotted cories, sodalis and trilineatus in my 55g. I have 5 sodalis and 4 trilineatus. They are both spotted, but have some differences. They usually all hang out, but I do notice the separate types hanging out amongst their groups.
If you had 2 different cories, they will hang out together, that's their nature. But, they would be happier having more of their own type to socialize with.