I was wondering how small your tank is? I have a 55. gal with bigger fish 4 male mollies livebearers, 6 Harlenquin Rasboras, 8 Glow light tetras,2 bushy nosed plecos, 1 large angelfish and 4 dwarf rainbow fish. I also have a 6 gal. in my Kitchen with only Tiger/Hybrid male endlers, red cherry shrimp, and the other is a 5 gal. with a female Tiger/Hybrid endlers. I also have a 2 1/2 gal. Hospital tank for new fish, sick fish that now has baby endlers.
If the tank is 5-10 gal. Go with all male endlers. They are like guppies but smaller in size. You can have a nice community tank with red cherry shrimp, and any non aggressive tetera, like glow lights, neon, Corys catfish, oto for algea control. Mine get along fine having all male. If you want Guppies the females are very plain and I think that the males are really nice looking for a tank to add color. Stay away from swordtails, Mollies as they tend to get big and are big waste producers. The endlers are really small so you can add alot of them like Black Bar endlers. They are sort of hard to find. I got my Tiger/Hybrid endlers on E-bay type in endlers or you can check out Swampriveraquatics for a nice selection of endlers she also sells on Aquabid.com type in endlers. Look online to see what some of these look like.