Reccomend an integrated tube Amp-under 2k

I think, given your speakers' specs and your desire for more dynamic power and greater clarity, that a Pathos Classic One Mk III would be something to explore. You'd get about double the Melody's output at 8 and 4 ohms (130 at 4, within your peak range for the speakers). The pre stage is Class A and true balanced, and has a pair of XLR inputs, which makes it more versatile than the Melody. It also has a remote, something the melody lacks. I think the Solid State amp stage might also give you the dynamic authority and strength in sound staging you cite as a problem with the Melody. I heard the melody in a casual listening sessions and thought it pretty nice, but that it would be bested by most others mentioned here (VTL and Rogue especially). I think that Pathos keeps its resale well, as it's got good reviews, looks great, and most importantly sounds great.

The Pathos Classic III is on audiogon now for 1500 for a Mk III and around 1000 for a Mk II. Just search for pathos. I wouldn't necessarily go for a Mk I since II had some good improvements that III inherits.