General information on my ball python

Hello! I have a 5.3 oz (150.25g) male ball python. I was just wondering, judging by the caresheet i've seen, it tells me to feed it anywhere between 13-20g mice. Is this accurate? Also, I planned on making a snake cage for it, as it is in a 30 gallon fish tank. I am fairly decent with my hands so any task shouldn't really be an issue for me. Could someone point me in the right direction for custom snake pens? Please and thank you!
-Dee

PVC is the best choice for a cage material. Wood holds heat well but it can be hard to properly clean.

That range is fine for feeders. Another method is getting a feeder the same or just slightly larger than your snake's thickest area. Just enough to leave a little bump at most.