Speaker recommendation. have $2,500

How about some Mag 1.6 planars with a sub?

How about Usher speakers. I have the x719 and really like them. I have heard Ushers floor standers and think they are excellent.

If you can find a clean pair, the Dynaudio 3.3's are actually quite good speakers, and they go for roughly $2,500-$3,000 used. They are also less forward than the C1/C2/C4, which is what many people find off putting about the sound of those models.

Of course, this recommendation assumes that you like the Dynaudio house sound, which you must if you like the C4's.

I've been told to check out Vandersteen 2ce MKII.

Yes, check them out.