First, you will need help before, during and after. Please read the article on self catering your wedding/event.

You are wise to plan some bites while the guests wait, but I suggest you don't use deviled eggs; people will be hungry, they will want several and deviled eggs in quantity take a good bit of lest minute prep. Raw finger veggies with dip, cheese spinach squares, so,em other non-drippy bites would be better. Also, you want at least 6 with 200 people- and make sure it is obvious from visiblity that a dinner buffet is coming, or some folks will try to make a meal from the cheese and sausage.

For amounts for the beverages, sandwiches and other choices, all are covered on the sandwich event page and the plan for 100 page, you can calculate your amounts- plan for 100 people's worth of beef and about 60 people's worth each of ham and turkey. If you want me to check them post them.

In order to serve the people buffet style you want at least 2 lines (4 would not be too many), or both sides of the long table arranged the same. If you have table seating, one option is to put the condiments (several mustards, mayo, etc) and platters of sliced tomatoes and lettuce, maybe pickles or a relish tray, on each table- this is where sandwich buffets usually hang up in the lines. You could put deviled eggs on this platter, too, allowing 1/2 per person plus about 2 extra- many less than needed in the appetizer situation.

If you have kids coming, a peanut butter and jam spread would be appreciated.