Class III verbs (those ending with -je in 3rd person singular) have two possible endings in 1st person singular: -u and -i.
-u is more colloquial, -i more formal. And it's also a matter of where you come from, I suppose. A person from Moravia is more likely to use -i, I think.
Does the order of words in such kind of sentences make difference? Will it be incorrect if I say "nepotřebuju vás"?