As you have a 8x68 barrel (ie .323) on the way and you already have a .375 H&H in my mind it would make more sense to go something closer to .35 cal.

You have stated that you are not interested in .35 whelen but how about something exotic in 9mm.

A 9x57mm might be a bit too boring for you but how about 9x63mm. Its ballistics as the same as the ones you are considering but if built on a .358 barrel you will have an easy supply of projectiles from <180gr all the way to 300gr.

George