Getting a new rescue tomorrow, poor snake.

I feel like if the age you are told is accurate he may end up being a little stunted growth wise. I would try him on a slightly smaller food item than he should be eating. Hopper mice are good because they move around a lot and can trigger a feeding response. But some people don't like using mice because of the fear of the snake only eating mice after that. So you may want to try a rat pup. Not quite as active but you are setting the snake on the right track food wise. Rescues often have mites so read read read on how to get rid of those little buggers.

Also, I tend to not like heat lamps. Most people here will probly agree. It's very hard to keep humidity up using lamps. They dry the air out a lot and they are tougher to regulate. The ideal setup is a heat pad regulated by a thermostat. A cheap way to do this (because thermostats can be expensive) is to use dimmer switches from Walmart. They are used for dimming lamps that don't have a dimmer on them from the factory. Basically you plug the dimmer into the wall then the heat pad into the dimmer. Grab a thermometer and monitor the temp and slide or turn the dimmer switch down or up till the correct temperature is reached.

If your keeping them in fish tanks, its notoriously hard to keep humidity steady. The only advice here is to find a humidity gage and place the probe in the tank. Then cover the top of the tank with tin foil or a piece of wood or something and spray the substrate down a bit. Humidity should be in the 60-70% range. Some basements are this year round so you may not have to worry. If not keep an eye on the gage and mist accordingly.

Hope his helps!