I don't think you can go wrong with either, especially at the ranges you mentioned. The .243 is certainly capable of taking deer. I don't hunt any more, but the .243 is the only caliber I ever used for deer and I never lost one. Shot placement, just like any other caliber is important though.

But, for deer, I would think that the 25-06 should be superior. I have no experience with this caliber. The recoil may be a bit more if that matters to you. Since you reload, ammo availability may not be that big of a deal either.