I totally understand and respect that decision.
For the record - I've put roughly 1500 miles on my P15, and much of that has been at highway speeds and in and around rush hour traffic. Disc brakes up front, Dodge Charger axle out back with drums and 3.55 gears, T5 5 speed transmission (for overdrive), 251ci engine out of a Desoto with dual carbs and dual exhaust. It starts up, it runs, drives, and performs well for daily driving activities. Runs straight down the interstate at 80mph if I want. I bought it to drive and enjoy and travel with. Since I have owned it less than a year and have been ironing out kinks in it (needed rewired, fuel pump issues, been sitting in a garage for some time), I think I'm doing pretty good so far.
All anyone on this forum will want to do is help you make the best decisions for you. Those decisions might be different than someone else might make. All we can do is provide advice and explanations as to how we ourselves decided based on what we are doing.
Good luck! I hope this brake job is quick and painless and you are enjoying your ride in short order!