If you want to shoot deer out to 1000yds, the 7RUM will be easier. But easier isn't always better. It will cost more to shoot. Let's make an assumption that the RUM will need to be rebarreled after 1000 rounds (might be less) and it costs $500 to rebarrel (will likely be more), then every shot costs you $0.50 of barrel life. The RUM will burn more powder as well (about %30 more), brass won't last quite as long, primers and bullets will cost the same.
I'd probably choose a 300RUM, as it has better barrel life and will easily reach 1000yds.
After all, the choice is yours. Neither of the rifles you are considering is a poor choice.
AJ