Any of those units would be good choices and all have the same EQ capability. Had the C2300 and currently use a C50. C50 warms up faster and is a bit better with electronic instruments, but is somewhat clinical in comparison on acoustic material (something I generally prefer). C2500 is a C2300 with a DAC - don't know if that would make a difference for you.
I'm not a fan of separate EQs in the home environment; extra cables = too much noise potential. Internal tone controls are inherently better shielded. Good luck & happy listening!
I'm not a fan of separate EQs in the home environment; extra cables = too much noise potential. Internal tone controls are inherently better shielded. Good luck & happy listening!