You don't need to make a starter but I would highly advise it. You can build up your cell count with one pack if you have time or bitch both packs, but a starter is something I wouldn't brew without. You can put both packs in a starter and just shorten the time on the stir plate.
Plus, it is a great reason to keep a pound of extra light DME around.
Primary: Old Bootlegger Imperial Porter, Mill Worker's Breakfast Oatmeal Coffee Porter
Secondary: Oud Bruin, Berlinner Weisse, Apfelwein
Barrel: Whiskey :P
Kegged: Mill Worker's Breakfast Base
Planned: Pure-T Pale with Citra, G-Town Brown 2.1, Muddy Banks Irish Red