If you really like gouramis, go ahead and get one. The dwarfs are somewhat disease prone. But your water is good. If you find one that looks healthy, go for it. The honey gouramis are supposed to be heartier. Just look at them a long time before you buy. If they seem lethargic, fins clamped or sitting on the bottom, don't buy. Sparkling gouramis would be another good option- cute, peaceful and small. Paradise fish are neat too. In your size of tank, I would probably only go for one or 2 at the most. Unless you do sparklers, you could do more of them. Remember, your guppies are going to start having babies all over the place, lol.