An overdrive transmission will make your truck more enjoyable on the freeway. I put an nv4500 behind my 230 and ran it like that for years. A t5 or a 3 speed overdrive as previously suggested will do the job nicely.
As far as brakes go, just make sure to maintain them and you'll be fine. I could lock up all four wheels on my '63 when I had drums and the single reservoir master cylinder. I think the biggest benefit to disc brakes on a daily driver is no adjustments to maintain proper braking power. Of course, if you're hauling heavy loads in the mountains or racing, I'd say go discs no questions asked.
