Refridgerated prep table ! ($1500 bucks) about 90 dough balls underneath and if needed another 48 (4 trays of 12) in an insulated bag if needed Rest. Depot $29.99
By the way this is Bar none the Most important and hardest aspect of the mobile business! Not just keepingthem cold but when to take em out and how long to come to temp with varying weather humidity and about 100 other factors -you know, wind direction, angle of the sun, Phase of the moon ...
have fun!
John