Need a 6th member....

[Ultimate Charizard]

Ok i wont go into the Exact Natures etc but wouldnt mind a little advice.
What ive been doing is going round with the Same 3 pokemon all game and now i got past Dialga im just starting to get to a 5 mon team. Now im looking for my 6th...

Currently....

Infernape
-Flare Blitz
-Close Combat
-Mach Punch
-Fury Swipes (plan to changewhen i get somethign better)

Luxray
-Thunder Fang
-Charge (may swap for Irontail)
-Swagger
-Crunch

Golduck
-Surf
-Water Pulse
-Confusion (may swap for Psychic)
-Fury Swipes (will be changed when i get something worth having)

Lucario
-Force Palm
-Flash Cannon
-Reversal
-Shadowball

Garchomp
-Rockslide
-Dragon Claw
-Earthquake
-Fire Blast (Would prefer Flamethrower/firefang)

And then i need my 6th.
I was thinking of getting a Leafeon but its gonna be a while till i get an Eevee.

And yes i know i have 2 fighting types though i see them more as Fire/Steel respectively despite what thier moveset says)
What bothers me is how little PP Infernape will have. Also is Grass knot worth it on him against Water types?