Integrating Expense data with Client Billing

I use the class list for my contractor  to link billable hours to clients on invoices. Now I need to download checking and VISA statements and want to link individual clients AND contractors to individual expenses so I can create a line-item on each invoice of that client's expenses and a detail printout of that client's expenses, to be included with the paper bill.

Can I set up a seperate class list within the same company (one for clients, for invoicing) and another for contractors/others for expense recordation? If not, can I create a new 'list'  for this purpose within the company on QB?  Hope this is clear.

Thanks

bowlboy