Livebearer Tank stock?

[phantomlink]

The next tank I plan to setup is a mainly livebearer tank so I had a few questions

I plan to have a few different types of male guppies, as well as many females ( I know of the at least 2:1 ratio ), swordtails, platys, mollies ( maybe ) and if it'll work out, one giant shoal of neons.

What kind of stocking options do I have? I'll use the 2:1 ratio as a minimum but I'll prob go larger like 10 female swords and 2 male. How many of each fish can I get away with? I've seen so many sizes for Mollies its not funny, whats their actual size in a 4 foot long tank? A guy who breed fish at my work told me Mollies are a fish that will grow to their tank if they have to, which means they'll dominate the tank and I cant have too many of them, but if they only do 3" or so I have more room to breath

[emc7]

I only put one species of live-bearer per tank.

[toddnbecka]

I had a trio of sailfin mollies in a 55, finally got tired of scooping out their growing offspring before they started spawning too. They dropped fry regularly, never ate any, and would have overcrowded the tank if left alone. Now I keep a Carapo knife fish in another tank to eat excess fry, my endler's livebearers also run amok and have to be thinned out occasionally. Cichlids are worse...