I ordered the module from GMparts.com Part number 84526978 and the price was $72.08. This is the module and wiring harness connector that plugs into the existing wiring. It works great and took about 5 minutes to replace.
Jeff
I just put on the TruXedo Sentry CT and it rolls up and if you want to take it out all you do is roll it up and reach under and slide the two latches and lift the roll up and take it out. The rails stay in place.