I know how hard it is to find pants for long legs - I'm not as tall as you two - only 5'9" but still have a 38 inch inseam! It would be fine if I were fat. For some reason they make those pants longer (feel bad for the short girls!) Anyway, while guy's pants are an option they really aren't a great deal. They won't fit as well because they are simply shaped differently. You may be happy just to have something long enough for once but in the long run the poor fit will start to annoy you.
Fit is everything on the hill. You want to look good, you want to be warm and you want to be able to move well. I would first look at Roxy
since that is a brand you are familiar with and seemed to have some success - they are a great company dedicated to women's performance. Most of the Roxy styles are fairly fitted 'boot cut' styles so they are slimmer through the thigh. If you want a looser fit I would check out the Bonfire Particle Pant
. The style runs long and it has a baggy fit, which is their 'classic' fit - room to move but still a nice fit in the butt and hips, which is what you won't
get in a men's pant. 686
also tends to run very long. I have a hard time fitting young girls who haven't hit their growth spurt yet, they just don't have the leg length for them - bad news for them, good news for us leggy girls.
There are some brands that carry longs but those are mostly ski lines that have some snowboard specific gear - it is great stuff, and will be long enough, just depends on whether you want a snowboard specific label.
Let me know if you need further help in finding the right pant for you!