I see a SR-007 MK1 in your future.
If characterising by sound the most amount of advantages.
Prefer the Lambda, Lambda Nova Signature, Lambda Pro, Sigma Pro, Gamma Pro, SR-407, SR-202 and the SR-303 over my LCD2's, all the Hifiman except the HE-6 (haven't heard it long enough nor on proper gear), every Beyerdynamic can's made except the vintage DT150, all Denons and nearly all the Sennheiser except the HD580/600 and the 800.
The original Lambda's have a godly mid-range and quite damn neutral sounding.
The Lambda Nova Signature is possibly one of the most neutral sounding Lambda frame earspeaker made, some say the Lambda Signature is more but I haven't heard one so cannot comment.
The Lambda Pro is most the dynamic and bass fulfilling out of the Lambda frame family, run this off a SRD-7SB/MK2 energizer off an amp with bass and treble dial and enjoy some quality low-ends. Sort of U-shaped.
The Gamma Pro's, very forward sounding but not bright, lots of quality low-end when music requires it, great for rock and metal on a well powered amplifier. Think of a Grado PS1k but without the mid range mess in the PS1k.
Sigma Pro's have a very unique 3d sound presentation as if you are center position of a live performance in the auditorium, not front row nor the last row, just in the center. Not much bass due to the distance and positioning of the transducers to the ears but no other headphone has been able to recreate the soundstage and holographic imaging of this stat imo.
SR-202, balanced sounding, bit bright sometimes but has great depth and layering capabilities. Sort of reminds me of a treble tilted Lambda Nova Sig. Bit bass light compared to some of the vintages.
SR-303, balanced sounding and sort of laid back and relax sounding having the traits of the SR-202 and the 404, bit bass light compared to some of the vintages.
Modern in production:
SR-407, easily better than the 507 and 307 in my opinion. The 507 is just damn sterile and cold sounding but a detail monster. 407 is sort of balanced sounding but supposedly some have reported putting on 507 pads makes it better in the detail compartment.
Others worth mentioning:
SR-Omega: Detail monster and very large soundstage
SR-007mk1: If the LCD3 had sex with the HD800 and had its sibling in fit shape with some balancing. To some it could be bit laid back or dark sounding.
SR-207, need to hear this in depth but well regarded here. Spritzer loves it and the SR-2170 package (SR-207 + SRM-253 amp) is a good $600 package to e-stat sound.