The light path of the Amici prism is longer than a standard diagonal. Your only solution may be to get a 1.25" version or just use a standard diagonal and view with left/right reversed images.
Note before you go changing find out the light path length of the 2" version, 1.25" version Amici and any standard diagonal you have (especially one that works) so you know how much travel is left on the draw tube when focussing at infinity.
What eyepiece are you using with the 2" Amici? Try a 1.25" eyepiece with an in-travel adapter such as
http://www.televue.com/engine/TV3b_p...23&Tab=_intrav