Medical Expense Reimbursement Plan Type?

Has anyone set up a Medical Expense Reimbursement Plan in Base Benefits? Not administration of it, just enrollment in the benefit. I guess it is similar to an HRA, but can accept either Employer or Employee contributions. Would this kind of plan be set up as a 6x Plan Type similar to an FSAs? Or would it make more sense to use a Simple Benefit Plan? The contribution amount would be a set amount each pay period and not an annual election like the FSA. Thank you.