I always say the same: drive it like it is. I do, and no problems, ever. You can easily upgrade the brakes by adding a dual master w/ booster, if you feel safer that way. drums all around is good enough, really. You can't drive that truck like it's a Camaro anyway, it's a truck.
If you want some extra top speed for the highway, ring&pinion kits are not expensive and a relatively easy job.
Not satisfied with the heater? Get an a/c kit from companies like Vintage Air, those things work pretty good.
Don't trust the generator? Get an alternator, any GM up to 96 (I think) will do the trick and bracket conversions are available fro all the vendors.
Seat belts? $25 each.
And I think by then you'll have a truck that is a great daily driver. I drive mine all the time, and the only upgrade I have is the alternator conversion. These trucks were made to work, so make her work!
(I am a fierce promoter of "keep it like it is", if you don't feel ok driving it like it is I understand, but this is just what I do)