Young audiophile metal head looking to level up speaker choice

@nitewulf My stepfather turned me onto Legacy with his same-as-your Signature SE speakers, which OH MY GOD!  He's had Vandersteen and Heron floor standing speakers both very very good and great accuracy, sound stage, etc.  But the Legacy line truly are incredible. They are efficient, flexible, and just electrify music unlike others.  I've heard some that are more 'real', warmer, fuller, powerful, better sound stage, smoother, resolving, etc.  But they all also LACK other things.  The Legacy, seems to have a really even balance of all things.  Though some may not like their style (the older ones were really....meh) like the much higher end priced ones are just...interesting.  For the money, for me, at the time $1100 for the Studio HD was money VERY well spent.

Metal Head here (and Jazz, and Indie Folk, and Blues, and Ambient...) Tons of great recommendations here.  Out of -your- choices, the Dyna are best, accurate and detailed but have more of a powerful sound than the others you are looking at.

Like others mentioned and depending on your budget: ATC would kill it. I ALMOST got a pair of the 19s, but they were just too large for my space (a few feet smaller than your room).

My vote is for the LEGACY STUDIO HD MONITORS.  Others suggested them too.  I have driven them with either a Rega Elex~R, or an Adcom GFA555 and honestly when paired with a decent enough sub (REL T5 or T7) these things really do rock, AND they are very detailed and accurate with great staging.  Legacy is used a lot by engineers and mixers in their studios as the Reference speaker and sound for what they mix. 
Personally what I love about these speakers is that they make me want to listen to ALL music---though they can rock, they aren't a one trick pony, meaning they don't fall on their face or are deficient in other areas with different music.

You can also customize/tweak them a little with the external cross over switches for the woofer and tweeter.