I like to make my own cages, and am known as the fool who can make a cage out of just about anything in a pinch.
I have one that was an out side vent made to big for the hole, so I laid in on it's side, meshed one end, door on the other and a couple of plexie glass windows.
I have some made out of sheling units, using the shelves as dividers between several cages or the floor & roof of larger cages.
The ones I like best are just a pine frame, meshing 5 sides before I put it together as a box. This keeps the chins from chew the frame, and keeps all ends hidden and out of harms way. I make up 2 doors for easy cleaning, have a stainless steel pan made to fit in the botton, and shelves, houses, tubes or what ever.
The mesh I use has 1/4 square hole, though I have used the 1/2 inch as well. I may have to break through a square here and there, to let the water bottle spout fit through, and things like that. If I ever need to close up a hole I just screw a block of wood on either side, to each other. It becomes a chew block then.
Your best bet is to look around at members sites, most of us have who have homemade cages & post pics. Jo Ann has some awesome ones. I think they are a little more expensive to make, but would last longer , more like forever.
Your only limited by funds & imagination when building.