Using Oppo 105 as an AV Receiver

Pretty new to the audio world and a little confused. My current set up is as follows
Marantz av7005,
Rotel RMB 1075
Monitor Audio RX6 Speakers
Sony BDP 780 - 3D Blue Ray
Panasonic GT30

My question is this. Looking for a high end universal player which I can use to stream music, play cd's but also watch movies etc. Thinking about purchasing an OPPO 105 Darbee edition. However can I use the Oppo as an AV Receiver/power amp on it's own? Would the sound quality be better with the units I have and the Oppo or would the Oppo 105 be sufficient with out the Marantz and the Rotel even being needed. I listen to music 60% and movies 40% of the time. As my Marantz and Rotel are worth about $1400 is there anything that would be better as a universal player that can act as an av receiver, amp and have much better sound than the 105 up to around $3,000 either new or used?

Excuse my lack of knowledge when it comes to Hifi as I am very new to this.

Look forward to hearing from you
The Oppo is not an AV receiver nor is it a power amp. The Oppo is a source device that you would use in conjunction with your Marantz preamp and your Rotel power amp, not in place of them. The Oppo would replace your existing Sony bluray player. I suppose it's possible for such a thing to exist but off the top of my head I can't think of any universal player that is also an AV receiver nor can I think of any universal player that is also a power amp.
The Oppo 105 has 7.1 outputs and a volume control as well as independent speaker level adjustments. It also has 2 HDMI inputs, which it can process.

So it could be connected directly to your Rotel amp and viewing device, but it can't power speakers by itself. I tried this with the Oppo 103 and it ran fine for a while, but then started to exhibit low level hiss which I couldn't neutralize. It also made low level clicking noises when employing various functions. I swapped it out with my Oppo 95, which also has the 7.1 outputs but no inputs. It seemed to run my 7 channel amp fine, and it had been running an amp without issue in a 2 channel system.

So I'd do some more research, or maybe phone up Oppo directly and ask them what they would advise.
As Runnin says, you can use the Oppo as your controller for an HT system (it is not an AVR but can do much of the same things). You should read the user's manual to learn how to do this.