I do bring them in, still too cold out there for leaving them. All I have is 3 Bantams and 2 bantam silkies (both rosters). They're 10 weeks old and the 'new' ones are 6 weeks. They seem fine though the fence these past few days. I'm actually worried about the Golden Sex Links bulling the Bantams cause they're already bigger than them. ( I call the sex links my Golden Girls)Oh, they are very susceptible to predators in that crate,
unless you are bringing them inside at night.
How many existing birds do you have?
Might be hard to fit them all into that small coop/run.
I use sand and PDZ:
You are going to have troubles with sex links which are more aggressive, and silkies, which are easily bullied and are susceptible to head injuries from pecking. I wouldn't combine the two in that small coop, and I personally would never combine the two ever. They are not compatible breeds.