ok, I would've said no to 60 silkies too. See how you manage 6-8 first. For silikies and cheap priceing to build, I would lean towards an A frame or similar style. However 1st choice is always to ask on craigslist for pallets or even better used playhouses. you can just add hardware cloth and a pair of nest boxes and a run to that.
One other thought, you'll want to make is secure from the get go, as you have several dogs.
One other thought, you'll want to make is secure from the get go, as you have several dogs.