stewart killick
Your best bet is to advertise for someone who can do the whole job. The contractor will either have a team already that can do all aspects or will contract out bits to other tradesman he uses regularly. Either way he will coordinate everything so everyone is on site when needed taking that hassle away from you. The order that things are done are very important and if you get it wrong you can end up with work having to be done twice . Also Trying to get yourself several contractors who don't know each and coordinate them to work together is very difficult and will at best a waste of money whilst people wait for each other, get in each other's way etc. At worst you will get an inferior job with no one taking responsibility for the finished article.