Since you'll be starting a long commute, the first couple of things that come to mind are all car related, such as a couple of Gerry Cans of extra fuel, extra radiator fluid, a roadside emergency kit, and so on.

Then perhaps I'd work outward from there on things you might personally need in an emergency, wouldn't want to lug around every day, but that you could store in a large shoulder bag or backpack in the truck. Items like a poncho or rain gear, wool blanket, first aid kit, and the like fit in this category.

From there I'd go for EDC items.

Overall I'd try to think about what you might need in an emergency and start a list, cutting or adding items by probability.

I understand working within a tight budget. Over the last year I put together a BOB a little at a time, waiting for sales and specials to come around, and comparing different brands with one another for the best bargains. I found in a couple of instances that even though prices on the internet were better than those offered at a physical store, the shipping charges made up the difference unless I was buying multiple items.

Ask stores both online, and in your area if they offer price match guarantees.

Other ways to save money are to shop on ebay, at flea markets and garage sales and so forth.