Just a thought, if you're only going to be doing outdoor dining at most once a month, I'd suggest you don't waste resources on it. I too have a corner and gave the idea up during my renovations. Assuming it's an open area, mosquitoes are plenty in the evening, even with fan or anti mozzie repellant. You would always need to clean the area before you dine there. And even without dining, you'd want to keep it clean anyway.

But if you plan to go ahead with it, I'd suggest to increase your budget. Wood decking is nicer. For roofing, I'd opt for clear tempered laminated glass and your gazebo support to use metal I-Beams. That's just me.