Well I don't have Western Fence Lizards but I have the Texas Spiny Lizards, which are one subspecies of fence lizard. I have had a female for over a year. She laid two clutches of eggs last summer (they will do this regardless as to whether or not they are fertile). The first enclosure I had her in was handmade...about four feet long, and at one end it was 4 ft high and at the other end it was about 2 feet high so it was L-shaped. I had large logs and dirt on the tall side and sand and rocks on the small side. I enclosed it with non-wire mesh screening. She really liked climbing around the walls. Then she got worms (from a moth I caught in the wild I guess) and nearly died so I decided to go with standard aquarium setups. These are much easier to clean.
Now this summer I got a male for her. I believe she already has a clutch of eggs on the way so it is too late for her to mate this spring. She might mate again for her next clutch. Anyway, the first day they were put together my male tried to mate. He has continued to do this but she (who is almost twice as big as he is) keeps running away from him. You can tell they display mating behavior when the male rapidly bops his head up and down and runs toward the female, sometimes even biting her rear legs. They get along well and they aren't in a very big setup at all. In fact, its probably too small but I have one for the male that I will probably move him to reduce stress on my female.
They are VERY jumpy. I don't really handle mine at all. The are smart. They know when you're going to feed them because they know what tapping the top of the cage means. Mine never fight over food which is what I was afraid they were going to do. My female is about 11" long total and she'll eat up to 8 large crickets at once. He'll eat 6 so it is best to make sure you have enough for them both.
AS for basking temps...I did what seemed to simulate the natural environment. It very rarely reaches over 100 degrees here but as long as you have your light concentrated on a nice basking spot that both of your lizards can access you should be ok. You need a full spectrum UV light also.
Since you are getting wild caught lizards quarantine them first in critter keepers and have their stools checked for parasites. This way you are less likely to contaminate the habitat.
I will say my female seems to be more happy with her man. If I were you I would try to get a male AND a female, maybe even from the same area.
I plan on getting some more females, but I have to wait until I can make it back to Fort Worth. I have a guy there who will hook me up.
Oh and I also have a pair of pink bellied swifts in a setup across the room. The enjoy looking across the room at each other 
If you have any questions let me know -- I'll be glad to help!
sfezio@hotmail.com
