Upgrade my integrated or use it as a pre?

Hello all. I was hoping for some insight. I have some money saved up which I'm thinking of putting into my system, specifically an amplifier. I currently have a Classe Cap-80 integrated (100W) which I am generally very happy with. I've been toying with the idea of adding a power amp (used Classe Ca100 or Belles 150A hotrod) and using my integrated as the preamp. If I were to go this route would I hear a substantial difference or would my integrated/preamp be a limiting factor. Should I just save for a better integrated? (Plinius, YBA?) Actually something like a used Plinius 8100 is within my budget. My main issue with my current set up is that while it sounds very good on small scale stuff it has difficulty with large scale orchestral music (loss of transparency, congestion) and I've been told that using seperate amp/pre would help in this department. Any thoughts on this? The rest of my setup is a Meridian 506.24, Tyler Acoustic Taylo Ref. monitors, Acoustic Zen cabling. The room is small/medium (23x14x9) so i don't think I would need more than 100W. Many thanks in advance.