Yours does sound much more natural in English, and per Linguee, "querer" is a translation of "to wish", although a very, very rare one. (http://www.linguee.com/english-portuguese/search?=source=wish) Did you try reporting that your answer should be accepted?
Big problem here. Subjunctive is a mood change tense. If you use the equivalent Portuguese for I want you to have a television. It would read Eu quero que você tem uma televisão. But subjunctive in this case with the verb tenha is just a supposition, not a definite fact. It's a vague statement because the speaker really doesn't know if the person really has a tv or not. Really, all the answers in this part don't take this in account, and don't go beyond the literal to the more subtle difference between Portuguese, and English.
DL's software made a mistake.
These verbs trigger the subjunctive: urge, demand, recommend, suggest, etc., but not "want".
Dear phaeIuis, I recommend that you not say: "I want that you have a televsion." ;)