"il faut vous proposer" is incomplete. It is not incorrect but in the sentence it's not correct because it would mean something like "you need to involve you" (to be volunteer) "Il faut vous proposer quelque chose" mean that someone need to bring something to you (a coffee, a topic, a task to do" Literally, "It's necessary to suggest something to you" would be translated by "C'est nécessaire de vous proposer/suggérer quelque chose"

The translation would be Est-il nécessaire de vous proposer autre chose?