Up until you mentioned that part about the possibility of an elk hunt, I'd have gone with the .30-30. The elk hunt kinda nixes that, maybe unless you handload. .30-30 really isn't intended for larger elk sized game, although Nosler does make a partition bullet for it, and Barnes makes an X bullet as well -- either of those can be made to do the job if you handload. Personally, I do handload so if it were me I'd just go with the .30-30 since it will easily do the bulk of what you want to do and can handle the elk hunt with proper handloads.
.45-70 will get the job done as long as the range isn't too long. It is more expensive to shoot and has more recoil, if that matters to you. Personally, I'd rather not have to deal with the heavier recoil when at the range or hunting lighter game, and I'm kind of a cheapskate.
In both cases, keep in mind that using Hornady's new LE ammo stretches your effective range about another 50 yards.
Since you are looking at a lever action rifle, you might want to check out the newer offerings that Marlin/Hornady have come out with. Both the .308 ME and .338 ME offerings are a significant step up from the more mundane .30-30 and may be more along the lines of what you are looking for. My only gripes about them is that they are so new that ammo and bullet offerings haven't really caught up with then -- yet. For the most part, you have the choice of the Hornady LE ammo (which is good stuff, even in .30-30 and .45-70) or handload with bullets that aren't really intended for the platform.