when i sported a mauser, i used a shilen barrel - and will do so again. i used a bold trigger, and probably won't again. i had the gun d&t'd for talley lightweights, and will do so again. i used a boyd's stock, and wouldn't do it again. i used a brownells bolt handle, and would again. i used an aftermarket aluminum trigger guard and floorplate (brand escapes me at the moment, but brownells carries it, and it has antelope 'engraving' on it) and would do so again. i used a tubbs speedlock firing pin and spring and would do so again (but only on mausers - definitely not on modern sporters). i used a lightweight aluminum shroud, and would do that again, too along w/ the 2-position side safety (a-la remington 700).
you will have more into the rifle when its all done than if you had just bought a new factory gun. but, you will have a very nice gun that can't be replicated by the factories, either. watch the weight of your components because 98's are pretty heavy actions to begin with, and it won't take long to have a heavy pig of a rifle built.
good luck!