I personally really love the Mack Snows/Super Snows and Super Hypo Tangerine Carrot-Tails. I'm sure you'll find some at the show that you love.
The gecko will receive genes from both parents, so they'll get one half the genes from the male and half from the female. A Mack Snow is a co-dominate trait, meaning a genetic trait where the heterozygous from of the gene (one mutated allele and one Normal allele for the gene, in this case a Mack Snow) is visually different from a Normal and visually different from the Homozygous form of the gene (two mutated alleles, in this case a Mack Super Snow). If you breed a Mack Snow to a Normal, each hatchling will have half a chance of being a Mack Snow (by receiving 1 mutated allele from the Mack Snow parent and one normal allele from the normal parent) and half a chance of being a Normal (receiving a normal allele from the Mack Snow parent and a normal allele from the normal parent). I don't know how much you know about genetics. Hopefully the way I worded it isn't too confusing. If you want more help in regards to genetics, you can read through some of the pages that I've linked to here: http://www.geckoglobe.com/geckoglobe/genetics.htm and this page that Judy, an admin here at BP.net, made: http://www.ball-pythons.net/forums/s...ad.php?t=52847
You can learn how to sex Leopard Geckos here, just scroll down a little less than half way down: http://www.geckoglobe.com/geckoglobe...ard_geckos.htm
Larger versions of the pictures can be found here: http://www.repticzone.com/articles/s...ardgeckos.html
How old are the two that you currently own? If they are barely visable and the animals are 9-12+ months old, they are probably females. Do they have the bulges at the base of the tail?