Lair Mistress, are these the hand/arm stakes that you were talking about on the other thread? I took this photo at At Home. I don't know the price of them but they are pretty cool looking. Maybe someone else knows the price. I will be back in the area of the store next week as I go back for an appt and will check them out.
Lair Mistress, you could even use the huge rolls of plastic from the party stores or the black ground cover from the garden stores for your enclosure.
My hubby enlosed our covered back patio several years ago and screened it. He made the support poles (actually not support, but places to anchor the screen. He made them the same space for windows in case we decide to totally enclose it later for a room. I love the screened porch. So that may be an option for you.