I have bred ASF's for a while so my recommendation is breed rats.

That said, starting up colonies is like waiting for hair to grow on a bowling ball. You put them together and check on them every day. Weeks and months go by and nothing. Then one day you look and the tubs are full of babies. After a while you pull out the weanlings and surprise, there's more babies under them. This goes on for a while until there's less and less babies replacing the weanlings. Time for a new colony.

Set up new colonies while the inital groups are in full production mode so you don't go through a dry spell.

Go with regular rats unless you have a very specific need for ASF's.