I have the basic books from Hornady, Lee, Lyman, Nosler but I might want to go off-book with some loads. So, I need a predictive tool, I guess. I don’t want to overfill or over pressure anything.
****************************
What you’re talking about is quickload, it’ll allow you to model loads from a database of powders and bullets.
Really what you should get first is a good chronograph. A good chronograph will do much more to keep you safe than quickload. All rifles are individuals so data from reloading manuals is only really accurate under the conditions and using the rifle they tested in the book. Knowing the velocity your rifle is actually giving you with a given combination is the best indicator a reloader has of pressure without going to a strain gauge pressure testing setup like the RSI pressure trace system.
Buy the chronograph first, then worry about quickload. Without being able to accurately measure velocity everything else is just a guess.
You clearly don't know what QuickLoad is for. It's a computer modeling software that must be 'calibrated' against real world testing to account for minute differences in everything from chamber dimensions to primer brisance to powder hydration. But it's brilliant for quick-n-dirty answers to questions like, "What happens to my pressure curve if I switch from BLC-2 to RL-10X?", that sort of thing. You need at least a decent chrono to keep it honest and preferably a chrono and PressureTrace2. A chrono and a PressureTrace2 make Optimum Barrel Time load development a breeze.