Necesito un amigo (male friend) / una amiga (female friend) que hable español. Ok, if it's so...just go to the: community/language partners and then send a message to the person who would you like to speak with. I am also willing to help you with your Spanish if you want. If you need classes, you can choose your tutor here: http://www.italki.com/teachers/professional Have a nice day.

You're right. - Necesito un amigo que/quien hable español.

I think you can say: Necesito a un amigo que hable español. Hopefully some native speaker can confirm that.

You can say: "Necesito un amigo que hable español" as Maho said, or "Tengo necesidad de un amigo que hable español". Those are the most literal translations, but you could also say: "Me hace falta de un amigo que hable español". Hope this answer helps you Vedat!. Keep learning!!