Bi-amp through receiver vs pre out to 2 channel for fronts

Are you getting the Atoll integrated or just a preamp?  I'm not sure why you're so high on biamping.  I think you're better off getting fewer but better amplifier channels for the same money and forgo biamping. 

Preamp so I can use my sub for bass management and attach the amp to the subwoofer. Otherwise I would have the full signal going to bookshelves which I do t want. 

The monitor audio manual must recommend three separate times to biamp so I thought here must be a reason behind their design.

To be honest I don't follow how you're incorporating the sub or what that has to do with your surround speakers, but I'd still get fewer and better quality amp channels -- just make sure you replace the stock speaker jumpers with decent wire.  To me, better amp quality trumps biamping with a lower quality amp, but maybe that's just me. 

I have really nice speaker cable from Canada called Phantom cable. It’s 12ga.

I can explain what I learned about using the subwoofer (for bass management) between the pre amp and amp instead of an integrated amp if you would like.

The Atoll 5 channel amp has two toroidal power supplies and all independent transformers in it, so It is essentially similar to having two two channel amps. The good thing for me is that it will be flexible if I ever expand my upstairs system into a 5.1 (right now it’s a 2.1) and until then I can bi amp which as you said is probably more mental than actually making a difference in sound. I do see your point that maybe I should just get a really nice 2 channel amp for now. I could still get the Atoll 100SE which is a nice 2 channel, but the 5 channel is scaled properly with added components and not much more money. I’m not sure f I would rather have anything over it at this point. 

I know you can’t tell over a generic recording, but you can kind of get the idea of the detail in this one. 

https://youtu.be/n6aFGttjhdM

The question still remains,  If you have auditioned the amps, which way did it sound best?  Forget manuals etc.., it's all in what the ear says.  I personally always keep my 2 channel system as simple as possible.  Fewer cables and interconnects is best for sooo many reasons.  You seem to feel strongly on going the 5 channel route on your sound though.  I say go for it that's what you want.  

Also please try to keep in mind that cables, like components need to work together in synergy.  Just because you have liked a cable with one system, doesn't mean it's going to work in another. I've found that Audioquest is one of the few cables I've heard (and I've heard many as I audition many systems) that is neutral enough to be used and sound good (because you don't get any sound signature) as I've heard.  Mostly their mid/high to high end ones.  Have never heard a truly balanced cable that's inexpensive, but that's to my ears.   Just get what you want and what your ears have told you to get and then jump off the boards, or you will drive yourself nuts, lol.