Sweet! I like everything about your new rig. ( same scope I've got on my 270)
The 7x57 is a great cartridge. Similar in ballistics to the 7/08. And you can't beat a Remington 700. Talley lightweights would also be my number #1 choice for rings/bases. For a bullet, I would start out with a 140 or 150 grain. No heavier. You might even try the lightweight Barnes tsx, in a 120 grain I think it is.