JDGreen is right - it's hard to know what can be changed without a description or picture. Some porches stick out from a house, and others are built right in. The stick-out kind is much easier to tear down and redesign.
As for who to turn to, you may start by driving around looking at other people's porches. Take pictures of ones you like. You could also clip pictures from magazines. If that doesn't help, or if it turns out to be a bigger project than you anticipated, go to a local contractor or home builder for advice and/or professional help with the project.