Follow the instructions for enabling the cruise control that is already lurking in your XL... You just need the steering wheel switches and then Forscan to enable it.
If you are anywhere near Atlanta, GA, there is a guy Frank who will install cruise control on you Maverick XL for about $280.00 complete. Actual factory cruise with steering wheel control exactly.
If you are interested, let me know and I'll send you his contact information.
I drove there from southwest Florida. He did the install in like two hours.