The best source for what I THINK you're describing is "trunk hinges" off eBay. I've used this exact unit in another project and it held a fairly heavy (80lbs) canopy upright in a stiff wind:
BMW E46 99 05 Steel Blue Trunk Hinges Mounts Shocks Joints Left Right Set | eBay
These trunk hinges use a hydraulic cylinder but don't search with that as the term - you're more likely to find bottle jacks and hydraulic equipment that way. In the auto industry they're referred to as "gas struts" and you'll find a million options with that as your search term.
Usually they're threaded at one or both ends, and you can get a variety of attachments. The standard setup has a ring end that bolts onto a mounting bracket, and the other end has a ball socket with a quick-release clip. That goes to another mounting bracket that has a ball to go into the socket. You can get these in all shapes and layouts, right angles, etc.
They're also available in a huge array of lengths and strengths.
Or did you want something else?