I wonder if part of the problem may be that your household is too busy with all the other children and he doesn't feel he gets enough time with you during the day. I do home childcare too. We have our three grandchildren and one other child at the present time, and I know how busy it can get. It sounds like your household is at least that busy. I'm thinking what I would try is to get him used to the crib during daytime naps for right now, and not stress too much over having him in the bed with you at night, as long as you and your husband can handle doing it that way. Or you might just want to consider scrapping the crib idea at all. We have fold up cots for our childcare nap times and when our grandson was about six or seven months old we started putting him on one of those cots for naps. He loved it. At home, he was using a crib, but also sleeping part of each night in his parents' bed. Now at 19 months of age, he has his own twin sized bed at home... a trundle bed that's been fastened so that it won't pop up to a regular bed height, so is low to the floor and safe in case he rolls out at night. You might want to consider just having a cot for your little guy for daytime naps and move that to your room at night so you can try to put him in it for part of the night to get him used to sleeping alone. Then move him into a larger bed in his own room... but one close to the floor, even if you just put a mattress directly on the floor until he's old enough to handle a higher bed.
The cots we are using, in case you're interested, are from the Regalo company. We purchased them from WalMart online and had the free delivery to our local store. They cost about $30 each and are much better than the type of daycare stack up cots that most centers use. We have found them easier to store, and we like them for sleeping because they are a bit higher off the floor than the stack up kind, and we feel that's better for the children. Another bonus is that if any of the children are going to be traveling, it's easy to fold up the cot and take it along for a familiar bed to sleep on while they are away. (Of course we limit that to our own grandchildren).