Sure you can! Get a copy of Fitted Knits by Stephanie Japel - she has lots of beautiful designs and has info an resizing that you could use for re-designing. Also, find a local LYS that has friendly and helpful creative types that will help you along the way - or grab KH buddy to take a look.
I've found the top-down method to making sweaters to allow for such design freedom (as you can see in the Fitted Knits book)
I do like the designs in the book but the fact that she tells you how to make them fit you is what opens it up to so many possibilities. That and the fact that the items in the book look like stuff you would have bought in a boutique - they aren't the same old "look what I knit" look - they are very stylish and up-to-date designs.
I bought mine from Amazon, I haven't seen it in a knitting shop yet.