Generally, you are enttitled to collect commissions earned prior to the termination of your employment. The employer must pay them in the ordinary course, as if you had not left the company's employment. The exception to this is when the company has a clearly articulated compensation plan specifying that commissions are not payable after the employment relationship terminates. You should contact an attorney to get the best answer for your particular situation.
In Arizona, the answer to that question would depend on the company's policy. For example, a company could lawfully enforce a policy that says that the second part of the commission is not earned until the company is paid, and that the salesperson must be an active employee at the time of payment. Perhaps a PA lawyer will weigh in on this question to let us know what the rule is in that state. Good luck.
My answers to questions posted on AVVO are intended to provide general information only, and are not intended to be legal advice. Employment law issues typically require a careful case-by-case analysis. Consequently, if you feel that you need legal advice, I would encourage you to consult in person with an employment attorney in your area.
The first question for you is: does your employer have a written policy regarding the payment of commissions? If there is no requirement that you be employed at the time of payment then you have a solid case as you seem to have no further responsiblities other than getting the contract signed.