I imagine male - male behavior would be facinating, I wouldn't risk it though. The animals seem to learn how to behave at an early age, and if they are housed alone, they are essentially delinquent rapists!
Let a young male be near females, and the non-receptive females will teach him a lesson about what WARNING COLORS mean. They will never attempt to mate with a female that is non receptive - it forces them to go through the whole courtship ritual, displaying, bobbing, shifting colors, uncurling their tail like crazy...
Plus, they will get pushed around by bigger males in the wild - in captivity, they don't know what it's like to get pushed around, and they think they can take on anyone - which is why my smaller male escaped and attacked the bigger one years ago...who ripped the skin off his jaw. Had he gotten roughed up as a child, he would have known better.
If you threw in two males who were never socialized, they will fight to the death. Similarly, if you throw in a male an female who were never socialized, the male will mate with the female - receptive or not.
The nicest, friendliest, most relaxed veileds I've seen were housed together as a pair or trio.
Botflies can infect reptiles, but I'm not sure if the ones here do. I know they'll get rabbits, cattle and other mammals... I swear, I hate them...disgusting parasites...
PVC coated HC is usually expensive the local ACE has it,but it's over a dollar a foot for 36" width.
What might be a thing to consider is patio screen frames. I just stapled my screen to the wood. You can buy that plastic frame from home depot, nail it to the wooden posts, and run the screen right into it, them clamp it down. IF they work with aluminum screen...