I had a rem 700 in 3006 that I had rebarreled to 7mm rem mag. The bolt face had to be opened up and a sako style extractor was fitted.
The gunsmith gave me a new magazine box liner, don't know if it was needed, but there are no feeding problems.
Once the bolt face has been opened up you can go with anything with a magnum bolt head is possible. Going to one of the RUM may require magazine feed lips to be opened up and maybe a new magazine follower.
Some people have even gone to a 338 lapua magnum on a 700 action, although I heard that a chrome -moly action is preferred over a stainless steel as it is stronger.
If you don't want to open up the bolt face then the 280 AI is probably your best bet as already mentioned.