You mentioned you don't have much $ to work with, as is the case with me. So I'll tell you what I use......Anything!!
Protect them from rain, preferably somewhat from wind and protection from predators and you're good to go.
You should count on a min. of 2 sq. feet of space per bird. even all wire cages work, I myself have used them and I have friends who are good breeders and use them. I'm not sure where you live, if it gets very cold then you should count on at least having three sides. Cages can be wrapped in plastic even.
The cages are very cheap to construct and you can make a wooden frame for just as cheap to set them on up off the ground and at a comfortable height. the cages will look something like this.....these are best for individual breeding but work for more than one pair if large enough.
http://www.tractorsupply.com/small-...house-trade-rabbit-cage-30-in-x36-in--2179677
You but the hardware cloth, guards to cover the sharp, exposed cut areas of the wire around the door, J-clips and J-clip pliers, some pliers to cut the hardware cloth with and are good to go. Tack the cages to the stand and cover the top with scrap tin or tarps.
I just put a scrap piece of 2x4 on the floor for a roost, a nest bowl, feed/water dishes.
This is just one of the cheapest and easiest ways to keep them.
