At that kind of dough, I'd be looking for one contractor... the general contractor.Place the burden on him/her for the selecting of the subs. However, make certain demands. - Proof of proper licensing and appropriate (and adequate) insurance. - Zero tolerance drug and alcohol clauses in all contracts: immediate removal and termination of contract if an employee brings drugs or alcohol on the premises.- At least three bids each for each subcontracted job.- Demand progress reports. Verbal daily. Written weekly or more often when there are problems.- What is your business? You might have unique security needs to consider. - A clear and concise change order process. There will be some, so be prepared to deal with it.Lastly, and perhaps most importantly, talk to others who have had similar projects done recently. Learn from their lessons... a lot less expensive.G'luck!