Breakfast Ideas for an Office Party with approx. 30 people.

Smoked Salmon. Cream Cheese. Capers. Bagels.
Fruit plate.
And electric kettle (keep it filled and ready or get a couple of them or one and Serving type themal hot water jar).
Both for tea..and for Packets of instant oatmeal.
Along with Honey, and jelly and jams.
Microwaved bacon--precooked stuff warmed and put on a warming tray.
Juices and Tomato Juice (orange, pineapple, tomato).
Toast and a toaster.
Butter. In a bowl (Go to craft store and get plastic candy molds and mold butter bits--1 buck a mold that makes 12 and make a bunch and freeze them to deploy)
Biscuits, Muffins, walnut bread.
Ham, Cheeses, fruits, Sliced fruits, Grapes, Melon balls, peaches.
Yogurt, cereals (offer some cups filled with yogurt and let them top them with granola and fruit). http://www.amazon.com/Square-1-75oz-Tasting-Sample-Glasses/dp/B004O5HW6W/ref=pd_bxgy_k_img_z

That's a big menu...but parse it down. Just throwing out ideas here for you. For office stuff, people only expect basic Costco, bulk food stuff for breakfast--so don't really knock yourself out. Think Holiday Inn Buffet.

"Easy Make-Ahead Room-Temp Breakfast Ideas for Office Party"

http://food52.com/hotline/14301-easy-make-ahead-room-temp-breakfast-ideas-for-office-party

Yogurt/Fruit/Granola Parfaits or an assortment of yogurts via Costco. Why not have it catered if its an office party? They supply utensils, coffee/tea urns and you'll probably spend less money, as they often have packages for office meals.

I would use a caterer !

I would make a breakfast casserole, which is bread soaked overnight in beaten eggs and layered with cheese, sausage and/or bacon. Lots of recipes for it are on the web. It is easy to make ahead and easy to serve. With coffee and some sort of citrus fruit, it is a good breakfast.

I like something savory ( eggs/meat/cheese items, like the quiche), something sweet ( muffins or scones) and something citrusy ( orange grapefruit salad )

I would just full size quiches. Buy the store bought crusts and make a few different ones. Ham and Swiss. Spinach mushroom and goat cheese with thyme. Bacon, caramelized onions, , diced tomatoes and gruyere. Onions, peppers, black beans and tomatoes and jack cheese. Bake them all the night before and just warm them before you leave and wrap in aluminum foil to keep them warm on your drive. Call your grocery and have a freshly cut fruit salad waiting for you to pick up.
Coffee and you are all set.

Perhaps mini-quiche? They are easily purchased at a bulk food store (Costco or Sam's Club) if you'd like to go that route. And if you choose to make them, they can be made ahead in bulk without taking too much time or money. Also easily customizable for variey!