First, the Sealed vs Ported is MYTH. Good modern Ported Subs perform very well in Group Delay measurements and are on equal footing with Sealed Subs.
Second, for your room size, I would definitely recommend Ported, and ideally multiple Subs, probably with larger Drivers than 10".
Not trying to blow you out of your room, but you have a lot of space, and Low Frequency Soundwaves will act on the total open-room volume.
This article outlines our test procedure in determining a subwoofers room size recommendation based on its max CEA SPL output while making room size and subwoofer distance assumptions.
www.audioholics.com
Did you place you gear in new positions?
Different than before?
(Removing carpet alone is not going to change your Bass.
)
This is a crude but effective way to possibly help you find better locations for Subs you may already have... or proper homes for new Subs:
Do the Subwoofer Crawl. It's the easiest way to find the proper placement location for your subwoofer to get the best performance and sound.
www.audioholics.com
You should avoid Klipsch and Polk Subs.
What is your Budget.