Stop, select speakers first!
Yash,
Welcome to the forum and good luck with your project.
However, you are approaching the system design in reverse.
1) Begin with the room you plan to use and establish your system budget. The room's volume and layout will help determine the number and size speakers you need.
2) Select speakers (not a small task, but the most important step) and should account for about 70-80% of your budget. This will in turn will help determine the power and minimum impedance capability necessary from your receiver or prepo/separate amp combination.
3) Then, research/buy the receiver or prepo/amp combination, as well as any needed source components (Blu-Ray, DVD, CD, Video Games, etc.).
Most modern day AVRs, have the requiste features, codecs, and connections necessary to build your system. They do vary in reliability, Auto-EQ system, and user interface quality.
Please provide us the room layout and dimensions (including height) and we can assist further.
I can not, but others may be better able to, help with specific AUS purchasing options.
Cheers,
XEagleDriver