When I am purchasing a home, what inspectors should I have come check it out.  

I always recommend starting out with a good general home inspector so they can give the entire property a once over.  From there, they will point out any defects they see and any areas that we may need to address further.  Most inspectors can give you some info on what they found, but it is best to then set up a specific inspector for whatever item there is an issue with. 

Should the inspector see some issues with the roof, it is best to then have a roof inspector come and check out the findings and give us his rundown on what is going on and how severe it may be.  It is always in your best interest to have a specific tradesperson out here to make sure you know all there is to know so you know how to proceed.

On older homes, it is also best to have the sewer line to the street scoped by a plumber to ensure there are no issues.  Many times, the trees in the area will penetrate the line with their roots and can cause a collapse that will be very pricey to repair.  Many homeowners will get it snaked out to clear the roots from time to time but eventually it will need to be replaced.

Always review your inspection report with your agent to ensure you are not missing anything important and can get the other inspectors to the house if need be and to also put together a repair request that adequately reflects the issues you have discovered.