Lenkolas, I know you want to do the right thing for your ferals, but I honestly think that if they can possibly stay where they are, in a place where they have developed a skill set to survive, it would be best for them.
If they aren't social, they will run from their relocation and try to return to where they came from, even if they don't know how to get there. I have kept ferals in an 8x8x8 cage for a month, and they still disappeared as soon as I released them. Older cats are particularly hard to retain in a colony. I've had better luck with cats aged 6 months to a year and a half. Overall, my success rate is only about 35-40 percent.