I am currently cycling my tank. Once it is ready i plan on stocking it with Mollies, guppies and/or platies... I was wondering though, what the smallest number of each should be in a group? My tank isnt that big, so i was planning on just getting about 10 fish... so i was think either 5 Mollies and 5 Guppies, or 4 Mollies, 3 Guppies and 3 Platies... but i am not sure if the second one will make the groups too small 
I am also planning on getting the same sex for each kind of fish. which is the best to get? Males or females?

I am also planning on getting the same sex for each kind of fish. which is the best to get? Males or females?