I'd go with the Castrol from those two choices.
My 98 302 eats about that much, with very little leaking from the oil pan gasket. I always use synthetic and prefer three choices at Walmart, Valvoline/Castrol/Pennzoil.
FWIW; I changed to Mobil 1 synthetic one time right before an 1100 mile trip, in about 2003, in my 302 Lincoln Mark VII. The car had never used much oil, maybe 1/2 quart after an oil interval of 4000 miles or so. My trip was with my mother and we split the driving, typical 10mph over the speed limit, 98% interstate, TN to SD. When we got there I stopped to wash the car in a stall place, and checked the oil and all fluids. The oil was about 80% of a quart low, in 1120 miles. I put that on the Mobil 1, and haven't used it since then.
Changing oil should not cause any change due to the brand, I don't buy that. I use synthetic virtually always(I have a 95 CV that has a rocker rattle, and I've played with different viscosities and cheaper oils(no real change)).
Try one or more oil stop leak products, some people have had good results from them. I've tried many with my 98 302, but so far the biggest help was fixing the original leaks of the oil filter adapter o-rings, pressure sensor, and balancer. Try Amazon for additives, they often have cheap prices for Add-On products(the prices change often, so put several in your saved for later list, and they will update you on changes). Regards,