Ive has a lot of luck with 4ever Products. Possibly could be a cheaper option, but they’re very durable, quick shipping, and most importantly convenient. They have a website with lots of options, but we’ve been getting just a standard white vinyl sign frame with top and bottom T style rails.
Simple to install. Cut an 8’ 4x4 post in half and concrete 2’ in the ground and leave 2’ about ground. Then the legs of the frame just simply slip over the 4x4.