I assume that folks are thinking it through before chipping in with their thoughts. The other challenge of course is that not many here are running Pioneer speakers. That's not a knock just an observation. But the result is that matching towers to your center will be a challenge - and they do need to be a timbre match.
You have a really nice receiver and if it were me I'd look at some other speaker options and plan on replacing the center as well. Keeping in mind that speaker selection is a very subjective thing and that our tastes my differ.
Option 1
Move the existing speakers in your bedroom and start fresh. Two Infinity Primus P362 towers (
$420/pr shipped), a matching PC350 center (
$210 shipped) and a pair of P162 bookshelf speakers (
$185/pr shipped) as surrounds. Total $815 and you can put aside the other $400 while you save for a bigger-badder sub. These you should be able to audition locally.
Option 2
I haven't personally heard these but folks here seem to be snapping them up and they would be on my short list if were looking.
EMP E55Ti towers (
$795 shipped) and a matching E5Ci (
$220 shipped), and a pair of E5Bi ($250) bookshelf speakers as surrounds. Total $1,265 shipped. Then start saving for a bigger-badder sub. You won't find these at your local store.