R12: How to consolidate installment invoices in AR

Hello,

We currently have a dilemma where we offer 12 month installment terms on invoices for some customers.  These customers have multiple orders each month, some may be the 12 installment terms and some invoices may be net30.  This can get confusing to the customer as they receive each installment/invoice individually each month.  They may have several invoices they get and have to pay separately.  I know R12 has Balance Forward billing to help consolidate, but you can't set up a balance forward payment term with installments.  Can you think of another solution?

Thanks,

Julia