Cindy, I would order at least 45 pounds brisket, plus all the others, and add 25 pounds sausage. Put the brisket last on the serving lines (you will need 3, or 2 double sided for this many people), and have someone serving it for the first round.
With the current order you are cutting it too close, because when there is more than one entree, people take more and some of each. Because the chicken is bone-in, you only have enough for about 70 people. Pork, about 90. Brisket, about 50.

You need some starchy side dishes, breads, and also an appetizer set up, here is why:

A self-catered buffet is a real challenge to the organizers, and things don't always come together as smoothly as hoped. By planning and setting up an appetizer area or "nibble table" which is ready when the guests begin to arrive, the cooks and servers have time to complete the arrangement of the dinner buffet. This is especially critical if there are children among the guests, or there is a wait before dinner, as at a wedding reception.

This does not have to be complicated. Three items, plus a punch, or two if one is alcoholic, are sufficient. Typically, include a fruit tray, a cheese tray and an attractive dip or spread; or you can go with a dinner theme such as TexMex with chips, salsas, Texas caviar and guacamole; Italian with bruschetta or antipasto; maybe shrimps or other cold seafood, if budget permits.

One appetizer service area is needed for each 100 guests.