This would be my top choices and are based on ease of use/reloading and the options with the best brass available.
1- 30-06 Lapua/Peterson/Norma brass
2- 30-284 Lapua/Peterson/Norma brass simply neck up 284 brass with a mandrel and load. Same or slightly more performance than a standard 30-06
3-30-06 Ackley same as the standard ‘06 but fireforming required.
All other options have few brass options or require a lot more work with expensive dies and reamers for a small gain. The .300 Sherman and 30 Gibbs will have the most performance, but dies will be very expensive and fireforming and making the brass is a lot more work than buying factory brass and shooting it or mandrel expanding it. The .30 Weatherby RPM would be the best choice, but I’m nervous with brass only coming from one source and it’s expensive and hard to find at times. Just my thoughts.