[Cynic]

1. Get a good quality shaker bottle. I have the Blender Bottle, but I've heard the Turbo Shaker is a good product too. It does not take long to shake up a PWO drink. Just take your bottle, the dry ingredients in a PB jar, mix with water.
2. Most everything else will require refrigeration. Cottage cheese, yogurt, etc. Beef jerky is a good protein source, but it digests slower. Nuts are good, but you'll need to combine it with grains sometime in the day for the protein to count toward muscle development. If you can put your stuff on ice while you workout, then put milk in your shaker bottle and use that in lieu of water. However, dairy products don't spoil in an instant. They can hold out for a few hours. If you can put it in an insulated bottle/container, you'll be good for even longer

Gym gear is more than just shirt, shorts and shoes.