A lot depends of how much work you are willing to do, probably the best would be Lapua 30-06 and then you would have to have and S-bushing die with several bushings to get it down to 25 cal, or if you had access to a 280 die and a 270 die and then the 25-06 that would probably work.
You may also have to turn the necks because they will be fairly thick by the time you size them from 30cal to 25 cal.
Depending on how hot you load them and whether or not you anneal the necks every 3 to 4 shots you could get 5 to 15 firings on the Lapua.
If you just want to buy the brass and load them, then I would use Winchester, you will probably get about half as many loads out of the Winchester under the same conditions.
Powder Valley has both in stock at reasonable prices