Well as a member of NADRA and knowing quite a few of the members I would recommend starting there. With that, any good carpenter, handyman or other contractor should be able to easily remove the deck.
It sounds like your biggest concern is probably how clean they leave your yard when they are done and for that I would call a few of their past clients to find out.
What are you planning on replacing it with? If you want to avoid "harmful chemicals" ever being used that limits your options. You may consider a steel framed deck with Ipe or some other sort of hardwood on top. Beyond that without pictures I can really offer any additional suggestions.
For more information:
Read Marian Keeler's "What are the best green alternatives to wood for decking?"