I personally wouldn't want to carry that much gear every day, but more power to you. I can fit everything I need for commuting into a standard rack top bag or a moderately large seat bag like a Carradice Barley. However, I leave a lot of clothes and supplies at work, including shoes, bath towel, soap, slacks and various snack foods. On a typical day, I'll carry my lunch, wallet, shirt, t-shirt, underwear, eye glasses, batteries, tools and tire-repair gear in my rack or seat bag.