Lookin for exterior bolt kit ie seingin arm and engine mount
Well, nuts and bolts are standard across industry, so you don't need some special kit.
I go to my local hardware store where they have open packs of all sorts and sizes. You put them in a bag and weigh the bag and pay per kilo.
Most screws I have swapped so far have been M6x12 or M6x20 with some odd M5 and M8 here and there. I usually get flanged screws and skip the washers.
I do so love screws. Then again, I am a mechanical engineer so the fetishism comes with the profession. If you want to talk screws joints for a couple of hours, I'm your guy.