The best Krell components for a dual purpose

I am installing a system for a client ,who has a Samsung HD/3D
digital tv,a pair of B & W CWM8.3 in wall speakers and an Oppo BDP-105 region Free Blu Ray player . He wants Krell pre-amp/processing/amp etc. for the quality and the ability to upgrade at the factory down the line.
He wants excellent stereo from CD, Ipod,Ipad or radio as well as from Blu Ray or DVD. The 18 ft. square room is all hard surfaces,- brick floor ,plaster ceiling and oak paneled walls.
We cannot really put a 5.1 system in because of it being a library ,and anyway his home theatre is going to be in another room. The equipment could be used or new. Any suggestions?
what do you mean by 'upgrade at the factory'? what makes you think Krell units are upgradeable?