I have to say that sleep issues are some of the roughest to deal with and our situation is not perfect at all but I will share with you our sucess with transitioning out of the crib.
I was a big fan of leaving my son in his crib for as long as possible because putting him to bed was easy but when he started learning how to climb out, I had to get him into a bed for his safety. I also had to consider that my son has Autism and at the time, he was into banging his head on the door if he wanted to get out of his room so just letting him cry it out wasn't a safe option for me.
I had a convertible crib that I had planned to use but he would not go to sleep in it... so after letting him sleep with me for a few nights, I opted for a queen sized mattress set on the floor (borrowed from the guest room). My husband set it up when we were away and took away the crib. When we returned, I showed my son his "new big boy room" and took him out to buy a quilt and pillows for it. I found some great bolsters to go along the side of the bed against the wall to make it cozier. He loved it! Once he was confident with the bed, we put the bed frame together with no problems.
We have since purchased a twin-sized daybed for him so there is more room to play in his room and there is still no question about where he will be sleeping.
I know you will figure out what will work best for you... you obviously love your son and will work with him to make sleeping in a bed comforting. Good Luck!