starwa, do you know that there is an entire forum dedicated to greenhouses on GW? i'm sure if you post there, someone, or many someone's will answer you.

that's how i came about to GW, i was researching greenhouses. i still haven't gotten one, but i sure have everyone's literature. i personally like the rion one for many factors, but i need to see it in person and haven't yet.

the people on the greenhouse forum will be more than happy to help you in your quest.