With the questions you ask I'd forget about 300 shots and build and learn to tune much more forgiving combo's. Really with a perfect tune you can get away with stuff that isn't recommended,with an off tune NO amount of good parts will save you.
I have a wideband sensor and plan on doing everything possible to avoid detonation. I plan on starting with a 100 shot and perfecting my tune with that and slowly moving on up. 300 is the most I would ever do so I'm trying to build my engine to handle it.