Call me old fashioned
I like the .30-06 for its versatility, reputation and ability. You need to do what you want, but since you asked for opinions, I'll throw my $.02 in.
First, you have nearly 100 years of information and history. With the .30-06, you can go from a 110gn bullet to a 250gn bullet. You didn't say what you wanted to do, whether you just want to punch paper or hunt, do tactical shoots, whatever.
Barrel life. With a good quality SS barrel, you are looking at thousands of rounds with a .30-06. Now if you are not going to shoot that often, that may not make a difference. However, if you are, then it is something you should consider.
If you are going to strictly punch paper, and you are going to sell the rifle, have you considered the 6br? Check out
http://www.6mmbr.com/index.html That is accuracy and a proven track record for paper punching. If I'm correct, the world record high power was shot with a 6mmbr. That is if you are looking for an entirely new platform.
Another thing about the .30-06 is you practically cannot go into a store that sells any type of rifle ammo and not find .30-06. Plus match ammo is readily available.
I am not against any other calibers, so I am not arguing about which one is "best". I am only sharing my opinion that-in your shoes-I would build the .30-06 into a rifle that you can do anything with.
The only question I have is what Jeffvn said about the 7 mag being the number one magnum chambering of all time. In his defense he said he thought but I wanted to bring up the .300wm. I believe this is still king of the magnums due to the fact that it is used by the some aspects of the military.
Hope this helps. And if you decide to sell it and your brother falls through, give me a call. I'll give it a good home
