Savannah monitor care

[Will0W783]

I just got a juvenile Savannah monitor on Saturday. I'd say he's about two feet long, including his tail. He was WC, and I did research online and am treating him with Panacur (fenbendazole) for internal parasites. Externally, he's clean. I fed him a dozen crickets when I got him home and he ate them right up, so I know he's eating, but he seems a bit thinner than pics I've seen online.
His setup is a 57" x 26" x 24" glass tank with a plexiglas hinged lid that has a small screen cutout to put the heat lamps on. I just got the tank yesterday, and am setting it up tonight. He's temporarily in a 30-gallon breeder tank. I am curious as to what the best substrate is for him- at the store they had him on sand, I've read newspaper is best on some sites, and others say a deep soil/sand mixture is best. Still others say cypress mulch. I intend to use a UTH and a heat lamp at one end, and a UVB lamp as well. The heat lamp and UV lamp will be placed on the screen cutouts, and the UTH will be on that side, slightly more to the center, so that it creates as good a gradient as I can manage. I know he needs to be at 85-95 daytime with basking temps up to 110 and 75-80 at night, which shouldn't be too hard if I put the lamps on a timer and leave the UTH on all the time.

I also am curious about the best feeding schedule. I have frozen rodents on hand for my snakes, so I can try to offer some of those as well. I have also read that raw meat and premium canned dog food can be used as treats. Any suggestions or what others do would be appreciated.

He's not aggressive at all, but struggles to get away when held and will try to jump out of my hands, so once his big tank is all set up tonight, I'm not going to try to handle him for a few weeks. I will just let him see that my hands bring water and food to him and let him get used to me before I try handling again. I don't want to stress him out too much.

I'll try to get some pictures tonight once I have the set up complete, but I'm hoping for some pointers on the substrate soon so I can make sure I have that all perfect for him before I introduce him.