So I just SR'd for a alright Zapdos on fire red, lv50.
by using from exp. share on all my pokemon and vitamins and power items, I can keep this guy from leveling up right? will I need to train somewhere else other then victory road and old chateau (Spd and SpAtk)?
What EV's are you aiming for? If Speed and Special Attack, just use Old Chateau and Fisherman Andrew, You don't need to bother with the exp. share. Pokerus and vitamins and Power items make it go pretty quickly, and you won't level up.
Just EV normally at the lowest levels possible with power items(in this case Anklet and Lens)They will give you +4 evs for that stat even if you are not training it.
so 1 ev+4 = 5. 52 EV battles for 252 stats, 2 w/o a power item.