The 30-06 will already have the correct bolthead, and 308 should feed out of the 06 magazine.

If you get the 7mag you will need both a new bolthead and a new magazine.

All the other parts are pretty much a moot point on either. Neither stock is that great or worth much money, and both barrels are of an unknown round count and only worth about $30-40.

I vote for getting the 30-06