1500 grams for a young female, but 1200 for an older female that has already laid quite a few clutches. I personally wouldn't do a male under 500grams, and the only way I'd do 500 is if he's producing plugs. I like to wait around the 600 range just as preference. As far as lowering temperatures, you're not required to and most people don't although some people do it.
The laying of eggs can vary because of the ability to retain sperm, so I won't be the one to give you a date on that and then you get mad at me. Also just because you visually see a lock doesn't mean you should expect babies.