Help me find the best greenhouse/sunroom, for me

[Rivka]

So i am moving and loosing my great covered porch and my orchid have gotten a taste of fresh humid DC air and i dont think they are going to speak to me if i drag them all indoors. I would like to figure out a way to keep them out for a very long as possible, though i realize that all winter is probably really if not totally pushing it.

here are the facts i have to work with:

1. i have a sturdy 10'x10' deck i would like to use, it has two tall brick walls on the south and east side.
2. I'm thinking lean too style to let the kitchen door(east wall) and or the office sliding door (south wall) open into the space.
   
3. i live in the DC metro area (7a i think) so it will get cold eventually, but no week long blizzards, usually. but yeah we get below freezing for at least one spell of not a few and it does snow from time to time (but not last year for instance)
4. i have a small collection of about 60 orchids and will work hard to control that number since i will be moving in a year or so across county and i already know how much of a hassle that is with 'chids
5. i still want to take up all the space i can so i can have it for multi use
6. most all are intermediate, not too cranky of plants
7. i am renting and cant trash the place or change thing up a lot
8. i hope to sell the greenhouse before i move in a year or so. though may get to sell it to the owners of the house if it works really well as a sunroom.
9. I'm not made of money, but do understand paying for something i really enjoy
10. i would like to use the space also as a warm mosquito free place for my soon to be 2 years olds to play, so i will be putting all plants up on counters and hopefully a sitting area in there.
11. i guess I'm looking for a sunroom to put orchids in really
12. im handy with tools, but don't have weeks and weeks to tinker on something, i have twin toddlers, yeah i know, im crazy for doing anything but the orchids need a bedroom too

so thoughts? links to awesome things? i have been searching the nets for a few days and I'm burned out, hoping folks know of great things i have missed. there have been some ones that may work if something better does not come along.