Noone as far, so here are some thoughts.

One question to ask is, will you be using the two sets together/daisychained for one source - what is the source device, respectively do you have a (B&O) tv as well....or plan to have.

Generally speaking I would think of adding a subwoofer tor that big room....unless you never play very loud.

The BL9’s certainly might be an option instead of adding the sub.

MM

First of all thanks for the answer Millemissen,

I've been thinking a little bit more about the Beosound 9000 and Penta's. And finally decided to go ahead and buy them, I had all this money saved for travelling in 2020, that well, it's been collecting dust under the mattress all year.... So as soon as our government let's us move again freely I'm gonna go see them, and if everything is ok take them home. 

I know they had the foam/rubbers replaced, so I'll try to do the recap as soon as I can too. Penta's as planned will be setup in the living room front area, while I leave the 8000's in the rear for now (all of them playing at the same time). Main source for them will be the Beosound 9000. And was planning due to installation layout to do the following:

Beosound 9000 -> Penta FL -> Penta FR  -> 8000 RR -> 8000 RL (all with Powerlink). On a nearby cabinet I'll setup a Marantz amplifier with a Garrard turntable that I'll plug to the 6000's (with low line filters). 

To be honest, there's still a lot of variables I haven't taken into account, for example how to manage the sound coming from my TV (planning on buying some standard 4K Smart TV like Samsung or Philips). I think the Beosound only has one aux input so I'll have to think about that and how to get around it. Since originally I wanted to use the aux input for the Bluetooth receiver I have on my 8000's now. 

I'm afraid however that even with the Penta's and the 8000's there's not enough bass to "fill" the room. I'm not a fan of playing music very loud, but well, I'm 26, and won't have close neighbors... Also I occasionally play some music that require great bass response, and I already feel that I'm missing it just with the 8000's. But checking the database here I see that not only the Penta's have twice the woofers found in the 8000's, but they're also bigger.

Too many things, and to many variables! 

Yes, indeed many variables there.

Hope you get it set up as you wish it - although, I am pretty sure, that it won't be easy.

MM

You can be sure to have enough bass if you buy the Penta's. I have a pair of Penta's in my home bar. I have also tried a pair of Beolab 9.

You do not get much more bass with the BL9 compared to Penta - and the treble is a bit more "harsh" in the BL9 (in my opinion).

The 8000's are nice speakers, but they lack bass -you will be surprised when you hear the Penta's compared to them.

Thanks for the note Steffen, I have to admit that lately I’m buying more with the heart and not with the head. Since I’ll be moving to the loft late this month, I want to have the music system set up as soon as possible. Deal with the Penta’s seems to be drifting away, since it’s seems now that the buyer wants to keep them. No regrets though, I would to the same if I had such pieces… So, I’m looking towards another pair of Beolab 8000 that are being sold together with a Beolab 2 close by.

My biggest concern now is how to properly fill the 170 cubic meters of open flooring. Currently, my Beolab’s 8000 are playing in a room with no more than 40 cubic meters, and I have to admit they’ve adapted quite well. But I’m afraid even two pairs (two as front speakers and two as rears) won’t be enough.

Any thoughts anyone?