For a 10 gallon, your options are pretty much limmited to:
Dwarfs (colisa lalia) - either a pair, 2 females or a single male. They get to 2". Keep in mind that these are not the hardiest fish and that the males will harass the females and chase them. As you say it will be planted, this won't be as serious a problem. Only the males are realy brightly colored but the females' silvery coloration is attractive as well.
Honeys (colisa chuna/sota) - a trio would be nice (1 male, 2 females). These are slightly smaller at 1.5" and hardier. The males develop lovely colors and the females are pretty cute too. These would occupy the top layers mostly and would leave the bottom and middle pretty much free for other fish such as a small schooling species (spotted rasbora comes to mind) or some tiny catfish (pygmy cories).
Sparkling gouramies (trichopsis pumilus) are also lovely and do especialy well in a planted tank. You will find them under the name of 'dwarf croaking gourami' as well. Don't confuse them with the larger croakers. Sparklers are tiny and a group fo 3 would make a lovely addition. If you are not looking to add more fish, I would get 5 and dedicate the tank to these tiny jewels - they realy are beautiful. The males have bolder markings. I suggest you get just one male and the rest female.
Croaking gouramies (trichopsis vittata)are another option seeing as you plan to plant the tank. I would stick to a trio (one male, 2 females). These get to 2". Though they are not THAT brightly colored, they have striking blue eyes and, like the sparklers and as their name suggests, they can 'croak'. This is usualy heard during courtship or when two males are having a territorial dispute.
If you are willing to go for just one gourami, the thick-lipped (colisa labiosa) and banded (colisa fasciata) gouramies are both lvoely fish, very simialr to dwarfs in appearance but hardier and, IMO at least, more attractive. They get to 3.5" and 4" respectively. The males are more brightly colored than the females. However, with these, you can only realy fit a single one in a 10 gallon but you could still include small schooling fish or small bottom dwellers as tank-mates.
Chocolate gouramies (mentioned by the previous poster) would not fit in your tank though they are lovely candidates for a bigger species set-up. They don't get very big themselves but they are fragile and, like mentioned, need to be in a large group.
Do you have any other tank-mates in mind? This could help you narrow things down further. I personaly would suggest you either go for honey or sparkling gouramies (or both; if you are prepaired to make this a gourami-only, heavily planted, tank - 5 sparklers and a trio of honeys - sparklers don't spend their time at the top as much as the honeys and, as the two species don't look very much alike and are not very closely related, they aren't likely to be aggressive towards each other. Plus, both are quite peaceful anyway and establish territories in completely different areas of the tank. If you stick to the gender ratios I suggested earlier, this could make for a beautiful, but also very peaceful, tank.).
anybody got any ideas! 
Pretty hard to find though, they aren't very common. 
