Are the supplications mentioned for those who wish to marry authentic, and what are the reported supplications for the same purpose?

There is no evidence for specific supplications (du'as) or particular Quranic surahs designated for marriage. Committing to repeatedly recite a certain surah or specific adhkar at a particular time without a legal (Shar'i) proof is an added innovation (bid'ah). Supplication (du'a) is a great act of worship, and a Muslim should ask Allah Almighty for their needs, including a righteous husband or wife. Indeed, the Salaf (pious predecessors) used to ask Allah for everything.