If you want it for elk, get the ProHunter. The G2 is just an updated Contender, so your caliber selection is more limited. A rule of thumb that I use on the Contenders/G2 calibers is that if you can safely run it through a lever gun, you can use in it the Conteder/G2. The Encore ProHunter opens up your options to almost anything that's safe for a bolt gun. Except some of the fat cased, high pressure rounds like the Ultra or Weatherby mags.
Don't worry about the 28" barrel. The rifle will be about the same length as a 24" barreled bolt gun. Hope this helps.
Andrew