318 piston's and quench

My first planned 318 build never came about because was not the right time. So I'm starting over. The car will be a daily driver and will have p/b & a/c, so my question is how much duration @0.050 can I have and still have the p/b @ a/c work. I looked into mopar's P4452759 .430/.450 x 260*/268* I read it's duration @ 0.050 is 221*/228*. Is this too radical for the p/b system? What c.r. would I need? I'm wanting a noticeable idle & give the little teen some extra zip. What would it take to get a honest 300 horsepower out of it @ the flywheel? Would a stall converter be a good idea as well? A local machine shop said to stay away from comp cams XE cams 'cause they can be hard on valve train @ be noisy. Thanks every one