I've the destro lock spec from elitistjerks
Destruction in Cataclysm | The Demonic Mage (4.1 Updated) - Elitist Jerks
as far as gear goes...this is what i currently have, vs my ideal pre-raiding gear should be, everything is reforged (theckout
WoW Reforge Calculator & Optimizer, it'll optimize your current gear based on your selected spec.) I didn't get the chance to gem my legs yet, just made them last night
if you really wanna go all out..run simcraft, get your weights, re-optimize the gear

..
but for now generic stats are fine for me..specially since they're pretty close to my "simulated" stats.
your stats for destro are:
Int >> Hit (to cap - 615 Heroics/1742 Raids) > Haste > Crit > Mastery
i'm a little shady as to where the haste cap would be..if there is one...and at which point to start going for crit vs haste.
As far as gems go, you should be gemming brilliant inferno ruby into everything you can..i think the meta gem is burning shadowspirit diamond, which requires 3 reds...which is perfect...since you'll be up to your eyeballs in red gems
"As a general rule of thumb if the socket bonus is less than 20 Int, or 30 of any rating stat, then it would be better to ignore the bonus and gem [Brilliant Inferno Ruby]."
which kinda means i'll need to re-gem a few of my items...
i think i came up with that gear list based on a few posts..here's one i still have bookmarked
[Destruction] A Guide (4.0.6)
the OP goes into pretty good details about what gear is best for pre-raid, and where/how to get it, which professions, etc
it is for 4.0.6...but i don't think very much has changed...if anything to 4.1