Advice on AV Receiver versus Separates


Starting from scratch here guys on my first Home Theater. Any advice would be appreciated.

I picked up a Marantz AV7005 pre-amp receiver from Best Buy for $705 (open box). I can also probably pick up the MM7055 for about $800.

Is this combo a good option for a 5.1 setup?

Should I rather go for a receiver instead?

I have heard great things about the AV7005, but not as much about the MM7055. Are there other separate combinations I should be considering?

I would like to spend around $1.5k for the receiver / amp&preamp so I have enough left over for speakers, etc.

Thank you.
aman4kr4
I thought bi amping would just double the power to the main speakers and improve sonic quality even at low volumes. Is this not right?

Only thinking about it as both this 8 channel amp and the 5 channel Mm7055 are around 800. So I basically get 3 more channels, plus what I believe is a slightly better amp.
I thought bi amping would just double the power to the main speakers and improve sonic quality even at low volumes. Is this not right?

No, it does not but, even if it did, why would you not just buy a bigger amp?
Ok. Got it. So what are the benefits of biamping?

Seems like I should just go for the combo MM7055 + AV7005 setup.