Accuphase a-70 is a good option?

Accuphase amps pair very well with Dynaudio speakers, and according to my experience are significantly better than the Mcintosh ones. However, whether or not the A-70 has enough power for your C-4 depends on how loud you listen to music and what type of music you listen.

Given the sensitivity of your speakers, my prediction is that you will typically used 2-3 watts. Consequently, the A-70 will break not sweat whatsoever except when playing big-band and large orchestra music. I am saying this because when I listen to large orchestras the meters of my A-65 (the predecessor of A-70) shows variation in the power requirements in the 100-fold and 300-fold interval. My amp does not run out of steam because the sensitivity of my speakers is 105 dB. However, with the C4 (or with most normal speakers for that matter) that will not be possible. The best thing to do is to try the amp in your system.

Good luck and keep us posted!
Paul

Two Accuphase power amps in bridged mode is a very good suggestion Dave.
However, to keep the budget close to the price of one A-70 amp I would
recommend two A-46 power amps instead of two A-70.

Two years ago there was a show organised by the Alpha Hi-End shop in Antwerp
where the Dynaudio Consequence speakers where by two A-46 power amps.
(The rest of the electronics were: DP-900/DC-901 player, C-2820 pre and the
PS-1210 power source.) I could not attend this show, but a friend told me that
the A-46 had total commandment over the Consequence speakers. Having said
all this, I still advise the OP to try first the A-70 alone. Sound-wise A-70
should be significantly better than A-46 (or two A-46 for that matter).

Orionpcgames, as I have written in my first post in this thread, it depends on the type of music you are listening and how loud are you usually listening to music. We can not help you unless you provide us with this information