I have had 2 No1's. A 243 1A and a 45/70. I still have the 45/70, I will never part with it.
As for your choice in calibers, If you intend to use it as a close range hunting rifle I would consider the 405 or the 45/70 as they are quite a bit lighter than the 458 or the 458 Lott. However, if you like the heavier Safari rifle the 458 or the Lott can be loaded with 350 to 450 grain bullets for Canada game.
If you want a rifle with some reach I would go with a 375 or a 338. I like the ones with the Alex Henry fore ends and iron sights. Those No1's handle like a fine shotgun.

2 Different friends of mine had No1's one a 375 the other a 458. I fired both of them, they shot good.