Both good choices. I think the deciding factor will be how long your longest shots will be. The 30-30 loses accuracy out past 200 yds, whereas the .243 is good to 300+.
My nephew dropped a deer with his 30-30 on opening day. Hit a little low and just behind the shoulder joint. It ran about 20 yds and dropped deader than disco. The bullet went through the animal and completely took out the heart.
Seen a lot of deer killed with the 30-30.