just to high light a few

1. OEM proton headunit has a very high treble boost. Choose your speaker wisely
2. Changing headunit make the sounds become standard, but then the various option between features vs sound is complicated to choose from, and of course a good 1 will cost the whole setup cost from your list.
3. if the features of the oem headunit is okay, there's always another way to just upgrade the sound, before you made up your mind which headunit you will be going after since it is the interface you gonna deal with daily.