VR1. Mineral or full synthetic

I think both of these would perform just fine as motor oil in your application. However changing oil also serves the purpose of flushing out contaminates that can accumulate in a high performance engine such as yours. In addition you also should be cutting open your filter to look for metal shavings or other things every time you change oil. So the reduced cost of the mineral oil and the additional zinc for your flat tappet cam would seem to be the right choice. Just be sure to change the oil often. For the way we use our cars, often is probably more defined by the number of passes on the track or the number of running hours on the street, rather than the milage on the speedometer.

Personally, I use the valvoline mineral oil in my race engine, and the valvoline synthetic in my modern daily driver cars.