You Will change things ! it happens to all of us .
Lots of trial & error - then success . You will hear things especially speakers in sound rooms - they will sound great .
a] pay attention to what components are be used to drive speakers ?
b] acoustics in these sound rooms are tweaked - usually big time .
I'm very familiar with you type of bedroom - lots of angles , lower ceiling , etc . Placement will be critical .
Finding a pair of speakers is critical but will be hard until you hear them in your room you will not know for sure .
I'm thinking [ and have been through this ] a speaker with more of an open sound will fill room nicely
I went through box style like KLH5's , Spendor A5's ,Golden ear 5's
Magnepan .7's
Right now I'm using & quite happy with an older used pair of DQ10'S
They are not necessarily better [ the spendors & maagies were great] but they SOUND better in my room [ its a basement with a low ceiling and has proven to be a real pain in the a$$]
You may do well to start with some basic [ less $ ] equipment and find your sweet spot
one thing that has been mentioned - Blue Jean Cables - very good all you'll need
also I'm a big fan of Rogue audio - the newer Sphinx is a real good " best bang for the buck" int amp ..
Good luck & don't forget to Listen to the Music ! You will get caught up listening to equipment .