I have been doing some more burger recon. It seems that there is a lot to take into consideration First, meat to fat ratio. It seems that if you go with a lean cut of beef, then it lacks that juiciness. Where as if you go with a modest fat content, you get a great tasting burger, but it shrinks all to heck, so you are almost forced to go with a bigger burger.
With this said, what would be a good size. 1/4lb or 1/3rd lb.
(Based on precooked patty weight.)….I always wanted to say that.
My own experience is that 80/20 ground beef produces an adequately juicy burger with a little less shrinkage. You might even be able to use 85/15 if shrinkage is a major worry for you. (Does McDonald's specify fat content in its manual?)
Depending on the price you want to charge, a 1/3 pound burger will probably look and taste better.
This leads into my next question. Burger presentation. I already know that it is unacceptable to have the bun bigger in circumference than the burger itself. What seems more pleasing, the burger being the same size as the bun or overhanging the bun.
My personal preference is for a burger just a little bigger than the bun--another argument for the higher precooked weight.
Condiments
I personally like romaine lettuce over iceberg.
Beefsteak or Heirloom tomatoes.
Kosher dill pickles.
Red or White onions.
Home made mayo or Helmans.
What condiments do you like?
I'm with you on the lettuce. Will you be able to get a constant supply of good heirloom tomatoes year-round in Michigan? If not, go with the beefsteaks.
Red onions are sweeter than white ones, and if you're going to serve them sliced rather than chopped, I'd use the red variety. I'm partial to hamburger dills on the burger itself rather than kosher dill spears on the side, but if you are serving your burgers on a plate, I'd go with the spears. If you mainly plan to sell these to travel, find a source of kosher dill chips and place them on the burger. Given all the time and effort you're putting into the rest of the product, why not give yourself a break and use Hellman's? You're going to need large quantities of mayo, after all. But what about ketchup and mustard? (Dijon, preferably.)
Next would be burger thickness. I don’t want to be anywhere near the (oversized, super size, biggie) craze. But what would be a good thickness of a burger. Keep in mind that it will be cooked on a griddle rather than a char broiler. Griddles have more cooking surface area than a char broiler. I have also been thinking about grinding my own burgers. I was thinking, If I could make the burgers into meatball shapes, I could fit more fresh burgers in the fridge, not have to worry about them being smushed…if that’s a word, and then give them an initial smash when they are put on the grill, then they will have those beautiful irregular edges.
What are your thoughts?….

I'd definitely form my burgers as balls and flatten them just prior to throwing them on the grill. You will also get slightly thicker patties that way. For a 1/3 pound burger, I'd say a 1/4-inch-thick patty would look beautiful, but that thick of a patty might not fill the bun.