Welcome from Kansas.
If you WANT to go with a roller cam, go for it. However, I believe your fear of problems with Flat tappet cams are not totally founded. Most, an fact all, problems I have seen with flat tappet cams has been operator error. I have rebuilt ant least 10-12 engines, all with flat tappet cams. I have never had a problem. Over the years of the 273, 340, 440 and 383 muscle engines (lets say 66-73), Chrysler made millions of engines with flat tappet cams. I doubt there were too many problems that were cam related. I am partial to the Comp Cams XE cams. They have steeper ramps than most flat tappet cams, and give excellent power. I have the 268XE in my 340. When you install a flat tappet cam use lots of GOOD lube. I only use Royal Purple assembly lube. Plus, run a good quality break in oil. Plus, don't let the engine idle for the first 20 minutes of operation.
