FYI, not to dis making your own, but I do have a bottle of a commercially available natural repellent containing several of the oils you mention. Smells great and is a nice light lotion in a pump spray bottle.
It's called Natural Herbal Armor. I absolutely love it, and even find it takes the itch out of a bite even if you put it on after you get bit!
Let's see, now that I have my glasses on, it's got Soybean oil, and oils of Citronella, Peppermint, Cedar, Lemongrass and Geranium. It's not cheap, but then neither are the oils to make your own.
