Hi... I think “NEED” would be grammatically the right option. Also “NEED” you can use it in a formal conversation, or as a suggestion. Yet WANT people use it more in an informal conversation between two friends for instance. For instance you tell your best friend... “Come on bro in order to make a good impression you also want a good suit”. Like telling him that if he doesn’t use a suit, he won’t make a good impression. Like “is obvious”. That’s my opinion. Depends on contest.