I don't know what you eat the rest of the day........ when I was working, I kept a bowl of hard boiled eggs in the fridge and would grab one of those before I left for work (I got up at 3:30 and left for work around 5:00-5:15), or toast with a slice of cheese, a slice of whole grain toast with some peanut butter; a bowl of instant oatmeal with a bit of fruit; a protein shake; carton of non fat greek yogurt or helping of low fat cottage cheese.
And don't forget, breakfast doesn't have to consist of only "breakfast" type foods........ you can eat whatever works for you, so long as it fits into your calorie budget.
Did your doctor/dietician recommend the 1000 calories/day?
I like Barb's suggestions, or oatmeal with chopped nuts and brown sugar and ground flax, or yogurt with nuts or a scrambled egg with vegetables in it. You want some protein and vegetables ideally. I agree you should forget about rules about what is a breakfast food. Nutrition and variety is what's important. Green tea with mint is nice.
How about a glass of fresh orange juice with a table spoon of fish oil.
It's better to opt for whole fruit than for fruit juices. With whole fruit, you get the added bonus of the pulp, which adds fiber. While juices have some vitamins, they tend not to be best for you, because of their sugar content.