Are you using EPM or are these stand-alone project schedules? If they’re stand-alone schedules, you could use cost rate table A for the sell rate and cost rate table B for the cost rate (internal cost). You could then add a calculated column to the resource sheet to show the sell rate multiplied by the actual work for each resource, and another to show the cost rate multiplied by the actual work. This approach is problematic in EPM because there’s only five rate tables and your resources will have the same rates across all projects. You may not charge different customers the same amount for the same resources.
You could also create custom cost variables and add them to the resource sheet. This works well in the resource sheet but won’t allow you to show those costs in the GANTT view.