Touch 'n Seal - 600BF Spray Foam Insulation Kit U2-600 Closed Cell - Standard FR
this is the kit i used, 2" walls, ceiling, over the engine cover and the wheel wells. great product easy to use. i just had my bus out this past weekend and its cool and quiet. i called around too, they all wanted me to come in but wouldn't give a price. the cheapest i have seen is 2400. for a 30 ' bus. i used two kits and took my time and got every inch. do it yourself and save yourself money and time.