go with the smallest cam with about 120 seat and 250 open, under 480 lift, about 220 duration and you might not have the fastest engine but it will be near impossible for you to break the engine. Stick with a roller engine.
I would place a bet, that your
oil cooler and lines have zero, nada, trash in them. the filter caught it all over 27 micron. Once again piece of mind is worth something but for grins after you remove flush and see if anything comes out and let us know.