Having a ceremony 3-4 months after being legally married

Me and my fiance have decided we want to be married before getting a house / starting a family and before I start school in January. Any suggestions on how we can go about doing the legak wedding in a few weeks, and holding a ceremony and reception in March? Maybe a "I do BBQ".

We do plan to announce that we are "paper married" so that there's no assumption that we are gift grabbing or whatever by having a party. But I really really want my dad to walk me down the isle, my niece to be the flower girl, all that traditional stuff.