I think option two seems like the best. If possible I’d add a BL2 up front. Depending on your room, wall mounted BL 6000s look and sound great as rears as well.

I would recommend OPTION # 2. It is what my basement set up is along with a Beolab 2 subwoofer. It is a great set up with an amazing sound. The wall mounted 8000's and Beolab 12-2's make for a great tradiotonal theater look as well. I do need a center speaker as you have to place under the television screen to complete the set up. --- Congratulations and have fun!

Also depending on your TV, you have one more option. In my case I have Sony OLED TV with the Acoustic Surface technology that when set up with an external system can take the place of the center speaker. In my case, I have BL8000s with BL 2 up front, use the TVs Acoustic Surface as center channel and have BL 6000 to the side rear. I think the BL 12s would be great as well.

One advantage of the Acoustic surface is that the voice literally comes out of the speaker or singer. It makes for a highly immersive experience. I have also tried many sub combinations and I find the BL 2 to work amazingly well with the BL 8000. 

if you want an acoustic lens speaker in the mix, the BL 3 is another good option and it matches the look of the BL 2 well. So BL 2 front and BL 3 back for symmetry 🙂

Thanks for all your inputs and ideas, they are greatly appreciated!

I have decided to go for two 8000's as front speakers - apart from being a lot cheaper than going for a 12-3, I expect them to complement the BL10 nicely.

I am still unsure which rearspeakers to go for. A pair of 8000's or 6000's will look too massive, but I see benefits going for either a pair of 12-2's or white 4000's - the latter I would prefer if they could be mounted near the ceiling, and apart from the cabling being more annoying that way, I'm unsure if the sound would be noticably worse.

@Aussie Michael: Can you elaborate why you'd prefer the BL-12's over 4000's?

@steve1977: I thought the 8002's where visually similair to the 8000's - am I wrong?

@Stkong: Thanks for the input. I will update when I have decided on the full solution :)

@Jaffrey: Thanks for the input. Regarding center speaker, I have already invested in and installed a BL10.

@Mikipidia: Any surround reciever with pre-outs for the appropriate channels will do, however a reciever with 12V trigger out is preferable. I'm using a reciever without 12v trigger out, instead I'm using an external 220v module with trigger out (link), connected to my recievers 220v's output. The B&O speakers are then connected to the speakers using powerlink to phono+trigger cables ())

link 

I do have a Marantz receiver that I connect the speakers and Apple TV 4K via HMDI to the TV. This is only because the receiver provides a lot of flexibility in the set up.

I have also tried just TV headphone out (no receiver)  to BL2 and then BL 2 connected to BL 8000 and set the Sony TV to send audio to headphone and TV at the same time and it also sounded great. Much better than I expected it to. This is only because the Sony’s Acoustic Surface technology does a really good job when complimented by other speakers.