"Who are you going to choose?"
Translation:Siapa yang akan kamu pilih?
I think a clearer translation is ... Who is the one that you will choose? Note that 'yang' makes the word order more specific and hence the order has to be yang kamu. If the sentence was about an inanimate object this is clearer. Which is the cake (that) you will choose? ... versus ... Which cake will you choose? Both are correct, but the first would include the word, 'yang' when translated into Indonesian. Hope this helps.