I would actually consider a 20 gallon long as that will lasst couple of years my CA king outgrew his 10 gallon in first 8 to 10 months.

This is his second year and he is now 30 inches so going for a 48 inch long enclosure . I think the 10 gallon baby size rule for Ca kings lots kings ,corns,rats is outdated .

They outgrow it so fast than slow down a bit and 20 long lasts couple yrs.