is this a male or female that u will have in the 10 gallon with tank mates?if its the male in ur avatar.then i would rule out a betta sorority :)
i just cycled my tank and will confirm tomorow its completed..i have 4 rosy red minnows(fat head minnows) which are feeder fish at a LPS..cheap,but rosy reds are actually beautiful fish despite what they are used for..theres not much on the web about them.though there are fish.and as the name states.they are rosy red in color.
though they can be mixed with the fatheads which are grayish.and look great together also...im not sure what else can be as i havent had any thing else with them..the thing is u got to watch for is bright colors,and large fins.anything that resembles a betta.or the betta will attack it..and possibly kill it.
here is a website that has a list of fish u can try combinations.it ask for ur tank size and filter.i would first choose betta and then go along with it.it will also tell u if ur tank and bioload can handle the fish or not and give some tips.when i did mine for the rosy reds and the betta.it said i needed atleast 5 rosy reds.and then my betta.
i could still add like 1 or 2 more rosy reds if i wanted.
hope i helped or gave some kinda choice.hopefully others will also post what they have now and tried and can give more tips :)