Largo's Assonant Binding is the level 51 single target snare/slow/ag/ac debuff. On some mobs it could be good not as a pulling song but a dps song (the agility and armor class debuff). It's really not your best choice for pulling though. For every component on a song, the mob gets to make a separate resist check. So when you sing this song, and say the snare component isn't resisted, the agility debuff isn't resisted, the armor class isn't resisted, but oops, the slow component got resisted - if the mob resists any part of the song, it resists the entire song, making this harder to land than the other choices.
Dirge of Metala is a 50% snare with no other components, making it the easiest to land reliably, which is really good for pulling when sometimes you have to land it on the first try or start over on the pull.
The level 23 snare, selo's consanant chain, is also a really good choice. It is both a snare component and a slow component, giving the mob twice as many chances to resist as dirge of metala. But if resists don't seem to be an issue at your camp and/or hos makes it land fine anyway, it's a better snare than dirge and a better slow than largo's. 40% slow for your pre-slowing needs, and the number on lucy's is 110% snare, as opposed to the 50% snare that is dirge. The main advantage is slow and snare combined in one song for the incoming.
Your actual buff choices look good for your group, and with the strong melee emphasis, debuffs aren't really a big issue. I figure mana song must be for the shaman. Darkvine or Dryad's or whatever should be flexible though, Unless you really really need it, it's not going to improve the group's performance. Unless it makes the healing easier. I usually use it less for the tank, and more for the non-tanks on ae's and such. The damage it absorbs is pretty limited. Nothing wrong with singing it, but I would think of that as my wild card slot, and choose from a number of songs.
Psalm of Veeshan for more damage shield (and maybe resists if you ever need them). Actually, it's either late, or we need more useful songs, cause I just can't think of any other song besides pov i'd really sing in that group. Maybe the new Jonthan's from katta if I have some good melee procs. But that's just gravy. Honestly, if you do any chain pulling and spend a good amount of the killing time away from the group getting your next pull already (which you probably can do a lot with that group dps), I would seriously consider having an overhaste song in that wild card spot, if not pov. Even though you have aura, aura poofs on them as soon as you leave the camp. Songs last 12 seconds after you play them. So they have overhaste from the aura as soon as you arrive in camp, and then if you give them a fresh hit of overhaste song just before you leave the camp, they have it for 12 more seconds while they're killing the mob and you're out of range getting another. You certainly aren't likely to lose much by dropping dryads.