I've found that with an inside cage, heating can be acomplished with one basking section at one end. This usually allows a nice gradient of heating down the length of the enclosure. With Hotspost what you want to hit, down to around 70f for options they can choose.
If this is the first time they've went down for you? You should deffinatly get breeding activity when they come up. Mine tend to wait a few days and get some food in them before they start. I just try to feed the female as much as she will take, as mine tends to not eat quite as fast as the male does after they come up and the male is pretty relentless in his efforts.
I think this will be the 4th year of them going down, coming up, and breeding, with no results so far. I deffinatly know it has at least a little to with being lazy on my part.
Mine have also started going down at different times. It seems to get earlier every year. I think it was around August they came up from about a 3 month nap or whatever it is.
I have a video I took a few years ago of the mating "dance" that I need to figure out how to put up.
Some really cool monitors to say the least.
-Jeff