I have a compact Jandd pannier, don't know the model name. I cannot quite fit my 15" laptop in it so it can be zipped closed but you may be able to get the macair in it, 13.3"? Jandd also sells a padded pannier just for laptops with pockets for accesories. You need a rack for a pannier so why not put your clothes on the rack and maybe mount a hold for you lock? There are also panniers if that's what they are called that sit on top of the rack. I could see one of these plus the laptop pannier working to cover it all in an aerodynamic way if that's what you are shooting for. Personally I'd consider a slightly large pannier. If I was commuting 46 miles round trip I might at times want the space to carry extra. But you are a MacAir guy. Gotta be sleek Peace