I need a good party to win against the Elite FOur, Gym Leaders, And everything in between.

My team is awesomesauce.
Feraligatr, Luxray, Tyranitar, Ho-oh, Venusaur and Machamp.
Do you have a game you can trade yourself with? If not, thats too bad. Still pick Feraligatr though.

I need every pokemon to be able to catch in-game before I battle the elite four but the luxray sounds nice

I wish I could do that, but I need to trade over an entire PC Box of pokemon.

Use this team, it's super effective against all the gym leaders

Typhlosion Ampharos Politoed Heracross Espeon (They only use the gastly line) Mamoswine