I just did a search for "south east Michigan pond installers" and found a number of companies. The only advice I have is to avoid ANY company that advises against a bottom drain and advocates rock and gravel on the bottom. Many of these people want to set you up with a pond that will require yearly cleaning, chemical intervention (read expensive) and fancy gadgets (read expensive) to maintain your pond. A red flag is the attempt to sell you a maintenance contract for annual cleaning. Look for a company that advocate bottom drains, no gravel on the bottom, settling tanks and separate, filtration systems. So-called "biofalls" filters and in-pond filters are grossly inadequate and a royal PITA to clean and maintain.
