Instead of buying a field box make your own. I bought a rolling chest like thing from home depot that has a pull out handle so you can drag it along. It was $40. I just used an air grinder and cut out a hole for the power panel. It has a tray of compartments for storing tools and a big tub for storing miscellaneous crap.
but def have;
extra prop 3$
screw driver to adj your low speed needle just in case (eyeglass kit .99)
I bought a good set of interchangeable allen screwdiver set things $14
adj wrench $3
fuel tubing and pump $12
paper towels $10 for 6
windex $3
volt meter $20
plyers $2
screwdrivers $5 a pack
and its really nice to have a 12 volt charger. If you need to you can just hook her up to your car battery instead of using a panel or field battery

If you have a harbor freight around go there. You can get your tools for CHEAP.

I was made fun of for a while as i just used a beat up cardboard box with duct tape.

And if your landings arent pretty and extra wing set is nifty. but that can add up. So dont hit hard! and if you do just make sure its straight