I bought lining poles from lion country, but once I got them, i decided next time i would build them out of pvc. If you do build yours, use the design of lion country's safety lining poles. I have 3 of them; they are great (you can turn the point around for storage.).
re holding blinds, we just build our own. if you can weld, just use rebar and get some camo tarp. I will try my next one out of pvc.