Hi! I had a chinchilla for 12 years :) It's been a while since then, but I'll try to answer your question as best as I can.
For the cage, I'd say to focus on the height rather than just the width, as they like to climb and jump. The bigger the better. You should also include lots of platforms so they can explore and exercise.
The bars should be metal and powder-coated (avoid glass or plastic enclosures). Spacing should be no more than 1-inch to prevent escapes.
You'll need solid flooring and an easily removable tray for easier cleaning.
Make sure the doors are large so you can easily access your pet and that you can secure the doors (they're crafty critters!).
Provide lots of enrichment such as wooden shelves, tunnels, and chew toys (nothing plastic and nothing too small).
In terms of getting them used to being handled, here are my recommendations:
- give them time to adjust, don't try to handle them in the first few days
- when you do approach them, do so quietly and slowly so as to not startle them
- feed them treats to entice them and reward them for coming to you
- sit by the cage and talk to them to get them used to your presence
- leave them be if they ever seem stressed or scared
- start with petting them first
- once they're comfortable with petting you can move up to picking them up with both hands
- never handle them for too long
- let them have out-of-cage time, but let them come to you and never chase them
- spend time with them every day
- establish a routine (they like habit)
- offer them interactive toys and dust baths so they associate your presence with positive activities
I hope this helps! Best of luck!
