I'd stay away from anything "shrill" and personally would go with a "New England Style" sounding speaker that has modest bass,creamy mids and highs that sparkle.....fact is though your talking using a forward sounding receiver (only moderately) that sounds at it's best with the same kind of speaker at some volume.
In "bringing a track star to a skate board event", it is starting out a little outside the box (and can't deny how nice that setup will be) you have 3 options and these are from my experience trying to find a good match for an SX-1050/smallish space.
1. Stick with a "proven for this receiver" JBL L"xx"/Pioneer HPM/equiv. "xx" mid-size from that era.
2. Go "New England" with ADS,Boston Acoustic, and even Polk's w/silk tweeters' (Polk Monitor 7s'/ADS L710s'/Boston Acoustic BA-150s'.....bigger but they fit tight against a wall.)
3. Or a "to hell with it" Bose 301.....I don't care what their weaknesses are, they fill up a small room with lower volume detail and have a soundstage that envelopes you....most small room bang for the buck speaker (that I have) that gets used everywhere. I'll always have a pair. (They suck cranked, but up to mid volume hold their own with speaks that are better/only a win.)
4. (Had to do it.) Swap out the truly great Pioneer SX-1280 you have and go with something that is a better fit for a bedroom. Pioneer SX-1010,Sansui...many of 'em, big Marantz. All are overkill but with these it is easier to "dig in" and find lots of options for a rich,rich "bedroom sound" that sparkles out of warmth.
Don't know where your ears are at but that is from my likes and experience.