I think I found it. Under $30 for the pair. unscrew the plug in doohickey and use the nuts from the old ones. I believe the spring is sturdier than the original.
Clint, I think the FoMoCo unit I linked to above is going to have the same diameter threaded body as the unit you have pictured.
Even tho I struggled with the tops crumbling over the last few years, I never had one slip around on the mounting surface. (I am only making them snug tight) Maybe a small bushing would make it more definitive in it's location on the frame platform.
I don't remember when exactly the springs showed up, but they were stock equipment on all GTs in 2006. The Thunderbird also used them. GT Guys opening bar had nothing to do with it. Some guys with 05 cars changed to the springs using Tbird parts. When cars were new in 05, the struts helped push the clamshell up to open. As they lost pressure, the springs became more popular.