You know I searched all over town, and finally found a hardware store with a nice fastner section. out of say 7 HW stores only one out of the way store had a nice selection of what I needed.
GO digging, take the screws with you so you know you're getting the right ones. Then you can look and feel what you are buying. I've found everyone of my T-maxx and savage scews at this place from hardened machined screws all the way to the soft silver ones.
I bought probably 200 misc screws for my t-maxx I use the hardened ones where needed, and the soft ones where I want the screw to bend rather than break off parts or screws in the r/c itself..
A screw kit may or may not have everything you need, but unlike ordering you can always go bakck for more. I bought a tackle box to put all the leftover scewrs in, and now I am never without.