Custom Fields are Hardly reportable.
You can use Customer Type or Job Type. Both are fine. Now you can run Sales reporting and financial reporting and profit reporting. If you see "Columns by" at the top of the report, see if it offers By Type. Or, you Filter ON a type.
For my attached example, I filtered on Customer Type = Residential. I also could have filtered on Job Type = Only Idaho, for example, to get Both References. And you can use Subtype, such as State and then County and then City, even = to 5 levels.