Are eggs (just the whites) a good source of protein before you go to bed??
There decent. A better choice is probably a slow-digesting casein-heavy protein like cottage cheese. Or Grow! (micellar casein)
Multiple sources are good too, some milk, eggs and meat. I usually go with a shake with about 60 grams of multi source protein though.
I usually drink a shake made with 2 cups of milk (skim), some yogurt, couple peices of cheese and a tablespoon of olive oil.
I am currently using a five different protein source blend along with Peanut Butter(fills me up better than plain flax oil) before bed.