I don't like the FSX ATC so I was checking for some addons. Is there an addon that works as the same way as in FSX for IFR and with new voices? Is Radar Contact suitable for my needs?

I'm using radar contact for a few years now with meatwatervocpack voices v2 (downloadable here in avsim library) and to make it complete also using it with multicrewxp (voice control). John

This question is asked quite a bit. Vatsim if you can match their hours at a location. If you fly in SoCal then PilotEdge is excellent.

ProATC/X is the new kid on the block with the brightest future, so it seems.

I'm using Proflight 2000 Emulator these days, as it seems to me the best of all the current ATC utilities. It has 101 voices, broken down by region, Can handle SIDs and STARs (Although it takes a little bit of setup for that!), It interacts with AI, although doesn't control them- (No current ATC utility other than default controls them) both on the ground and in the air. It can do VFR flightplans. On the negative, it does take a couple of extra steps, but it's pretty easy. Here's a full flight video for an example