Hello FireWaterEarthBear. :) You do seem to have too many sweepers, but I'm hoping to fix that by giving you a defensive Pokemon. Changes will be in bold.
Gengar @ Choice Specs
252 SAtk / 252 Spd / 4 HP
Timid Nature
Giga Drain
Shadow Ball
Thunderbolt
Focus Blast
Destiny Bond and Toxic on a Specs set are a no-no. So I replaced them to make an extremely common but effective set. If you want more bulk, you could try:
Gengar @ Black Sludge
252 HP / 200 SDef / 56 Spd
Calm Nature
Substitute
Giga Drain
Shadow Ball
Focus Blast/Thunderbolt
Ferrothorn @ Leftovers/Rocky Helmet
252 Def / 252 HP / 4 Atk
Relaxed Nature
0 IVs in Speed if Gyro Ball
Leech Seed
Stealth Rock
Gyro Ball/Power Whip
Protect
That's a pretty standard Ferro set.
Infernape @ Life Orb
Ability: Iron Fist
Adamant Nature
Mach Punch
Close Combat
Flare Blitz
Thunderpunch
To be honest, I don't think he's going to survive long enough to set up Swords Dance. So I changed it this. Iron Fist would be the preferable Ability here.
Alakazam
Looks fine.
Gyarados @ Leftovers
252 HP / 252 Def / 4 Atk
Adamant/Jolly Nature
Substitute
Dragon Dance
Waterfall
Ice Fang/Earthquake
Since you had a problem with defensive Pokemon, I decided to give you a Defensive Gyarados set.
And the last Pokemon..Not the least... You needed some Special Defense so I suggest..
Chansey @ Eviolite
252 SDef / 200 Def / 52 HP
Calm Nature
Toxic
Heal Bell
Wish
Seismic Toss
S-Toss means Chansey isn't Taunt Fodder. This Pokemon is purely team support. If you want, you can change one of the moves(not WIsh) for Protect.
Good luck with your team. And have fun!