Prop(s) is a good idea. (I keep a plastic B1 prop in mounted in the bilge just to get me home; never used it, but its light and cheap, and rated to 300HP.)
Definately a new seawater pump impellor. (I keep a whole impellor, and housing kit, bolts included. I usually keep last season's used impellor on board too, as its easy to toss to a friend when needed.)
Lots of Zip Ties, the high tensile kind with metal tooth, not plastic.
New tube of 3M 4200.
Several hose clamps of various sizes.
Full set of cheap tools in plastic kit from Target.
Nice set of Craftsman sockets. (Prop nuts.)
12" piece of 2x4 for changing props.
Always carry my cockpit cover too, in case I do break, and have to leave it for a few hours. (Did that once, without the cover, and came back after dark; boat was a mess.)
I've fixed several boats with these above parts, including my own.