Formin a Battle Tower Team?

[Megaa]

So, I have many pokemon lined up to compete in the Battle Tower. I enjoy training them up, but I have so many that I don't know what would make the best team. Also, the movesets and items are as they are now, I would like recommendations to make them better. Also, I'm curious as to how I would get my hands on the Boosting Berries (Notably Leichi, Salac, and Petaya), short of getting to Mirage Island for Leichi. So, the candidates are:

Porygon-Z@???
Modest Nature, Adaptability
EVs: 252 Speed, 252 Sp. Atk
- Tri-Attack
- Nasty Plot
- Shadow Ball
- Ice Beam

Hitmonchan@Life Orb
Adamant Nature, Iron Fist
EVs: 252 Attack, 252 Speed
- Drain Punch
- Ice Punch
- Thunderpunch
- Mach Punch/Bullet Punch/Close Combat

Yanmega@Stone Plate/???
Modest Nature, Speed Boost
EVs: 252 Sp. Atk, 252 Speed
- Bug Buzz
- Aerial Slash
- Giga Drain/Ancientpower
- Detect

Houndoom@White Herb
Modest Nature, Flash Fire
EVs: 252 Sp. Atk, ??? (Migrated from Emerald, dunno where the other EVs went)
- Sunny Day
- Overheat
- Solarbeam
- Dark Pulse

Muk@Chesto Berry
Neutral Nature, Stench
EVs: 252 Defense, 252 Sp. Defense
- Curse
- Rest
- ??? (Sludbe Bomb is now Special, can he get Poison Jab?)
- Earthquake

Ninjask@???
Jolly Nature, Speed Boost
EVs: 252 Def, 252 HP
- Baton Pass
- Substitute
- Swords Dance
- Slash

Rhyperior@???
Adamant Nature, Solid Rock
EVs: 252 Attack, 252 Speed (I know...)
- Earthquake
- Stone Edge
- Crunch
- Thunder Fang

Those are pretty much my choices, and I need 3 that I could use. Thanks for any help. :)