All Great advice to be sure!!!

What you load and shoot depends on what you are trying to accomplish, and Krags are almost human in their love of "Food!"  Some Krags LOVE the standard 220 gr RN, while others thrive in cast-boolit land.  Some feed spitzer bullets reliably while others hang up and fight you on the subject!  The best advice I can give is to find what works best and most accurately in your Krag! 

I shoot 220 gr RN Hornady Interlock bullets with 40.0 grains of IMR-4350 and a CCI-250 primer - as close as you can get to the original .30 Army round.  However, I have a friend that WINS matches with a 150 gr RN bullet.  Again, find what works best for you!

As for Brass, I have literally hundreds (several) of RP brass that is more than 20 years old, and some more than 30 years.  I also have a few hundred Winchester approaching that age too.  I have some of the new Hornady and new GRAF brass too, although I haven't used those yet.  I find the Remington brass right up there on the ole durability scale, and I think the Winchester brass looks much prettier/shinier than the RP.

One final thought:  There is absolutely NO reason to try and get velocities and trajectories that approach 30-06/308 numbers!!!  Krags do just fine lobbing the bullets in at under 2400 FPS (my rounds are right around 2000).  The hotter you go trying to get those flat shootin' velocities, the more you risk damaging your rifle and shortening the life of your brass!