i have a long taile grasslizard in a ten gallon tank. is this big enough for him? he is about 12.5 inches total length and 2 inches snout to vent. is it big enough to house a pair? or a trio? these guys are awsome and i'd like to breed them, so houw would i go about sexing them, the guys at the store... even the one that knew a lot about LTGS did not know how. do males have enlarged pointy scales by the vent (sorry its early i forgot the technical terms) or a thicker tail? we tried comparing head sizes at the store but that did not prove too useful.
also, since this did not get answered bellow, i was wondering if i coul keep jeweled cury tailed lizards outside in a screen cage? im in san diego. if i can do it though i would like to do it with no supplemental heating, it was very expensive to set it up for my bearded dragons and i don't want to spend it again, i want to keep them outside to save money as i am kind of short right now and he needs a new uv light.

thank you for your response
-jake