We had the same problem with our older media console as well and found the easiest solution for us was also mounting the tv but also finding a new console that the side speakers fit into that wouldn't disrupt the sound. The subwoofer I'm just not sure about since I know those are usually best placed in the back of the room as opposed to the front. If you are set on the IKEA console maybe just getting a sound bar would be best instead of all the current speakers. I know our style is different from your but here is what we did

I would find a way to do away with the large speakers. Or you might consider building-in shelves with a combination of closed and open storage to fit your needs.

Replace all those speakers with Speaker Bar with built in Sub Woofer

http://www.ecoustics.com/products/yamaha-yas-101-sound-bar-speaker/

I agree about the speakers it took me a long time to get my hubby to change over but now at least i don’t have to decorate around the speakers BTW I love the Besta system from Ikea