i am looking for a tent to go to a festival in but we would like a porch in it to keep all our bags this will need to be quite a big space

I wasn't sure how much space you needed so I went with the big MSR that you can add additional space to it, if you don't think this one is big enough. Or something like the Habitat 5 has covy holes for you to stash your bags in & is tall.
Truly massive, the floorless MSR Board Room is designed for multi-activity camping. Versatile add-on components (sold separately) let you configure the shelter to fit your needs and the weather.

    * It's the perfect shelter for large groups that like to be outside no matter what the weather; it features 2 end doors and 1 side door
    * Versatile modular design can be adjusted in a number of different useful configurations, from open to buttoned up
    * Add the MSR Screening Room and/or the 2- or 4-person Bunk Rooms (each sold separately) for even more options
    * Add 1 or 2 zippered Mesh Walls (each sold separately) for added privacy and bug protection
    * Interior peak height runs the full length of the tent, maximizing useful area
    * End door awnings allow protected ventilation in nasty weather; comes with solid end doors, but Mesh Walls can be added for ventilation

MSR Bunk Room 2 can be added to the Board Room (sold separately) to create an enclosed, bug-free room that accommodates 2 people.

    * Large zippered doors on each side allow Bunk Room to zip in with pass-through convenience
    * Bathtub floor and full netting enclosure keep bugs out and maintain maximum ventilation
    * Adds 32 sq. ft.
    * Interior peak height: 75 in.