There are some nice pictures of P velifera here
[URL="http/diszhal.info/english/livebearers/en...ia_velifera.php"]http/diszhal.info/english/livebearers/en...ia_velifera.php[/URL] As you guessed there are slight color variations in wild type mollies. In domesticated mollies, thee are huge variations in color and fin shape. I keep a large female molly that has a lyretail like the one in NoSoup's picture. Mine does not have a sailfin but is a healthy robust fish for her type. I am a bit concerned about the look of your female. She appears to be stressed in those pictures. Something seldom brought out correctly about mollies in general is that they require rather hard, high pH water to really thrive. A lot of people will advocate salt for these fish but I don't find it necessary as long as the water is fairly hard. In my case hard water is easy, I just open a faucet and fill a tank with it.
A source of nice mollies is swampriveraquatics he often advertises on Aquabid but has no mollies listed there right now. His own web site does show some nice sailfins but at a high price. Truly nice fish can be a bit dear.
My no so fabulous lyretail female with some fry at 18 days after giving birth. Shown with a few of her fry.