What ever you decide, make sure that the person, or company you hire to remove the trees is INSURED!
..and get a copy of his insurance certificates for liability, workers comp, and casualty, and be sure the certificate shows YOU as a certificate holder.
It doesn't cost anything, and contractor should be able to have his insurer supply you with a certificate (showing you as a certificate holder) via email in just a few minutes.
Do not let any contractor work for you who does not FIRST supply you with a written estimate, AND the insurance certs I mentioned earlier. PERIOD!
...btw, for residential contractors of all sorts, Angies List works well for verifications and opinions from past customers.
Just my 2¢.