Longer hair will make you look shorter, and it visually drags your face down. Volume on the sides will add weight to your face, so your best option is to go for some height (not big hair, of course) and a length that allows some movement.
If you've been going to the same hairdresser for awhile, they should be able to suggest something that both suits you and works with your hair. My hairdresser actually doesn't like pictures, if you come in saying "make me look like that". I use them to illustrate things I like or would like to accomplish, only. He has told me no before.
I found one site online where you can upload your pic and apply hairstyles. Unfortunately, I don't remember where that was. I bought the Cosmo makeover CD, but it's crap, so don't waste your money.
Some of the more progressive salons offer that kind of service. And you can have someone creative give you the first cut, then have your regular hairdresser keep it up (go in early for the first one, so they can easily see the cut - hair grows unevenly and they may not be able to follow if you wait too long)
Oh, and one final makeup tip - contour or blush under the cheeks doesn't fool anyone, so don't even try