Leah follow your heart on the co sleeping thing. I think people have strong ideas either one way or the other. If you are comfortable with it then it shouldn't be a problem.
I don't mind it but as I'm a light sleeper I found that their little snuffles kept me awake.
Caleb was in out bed for about 2 weeks then we put him in his cot. I used a oil filled heater to keep the chill off his room and he adjusted well.