Assalaamu alaykum. Is the following hadith authentic?
Abu Hurayrah narrated that the Prophet, sallallaahu 'alayhi wa sallam, said, "The person in the lowest level of Paradise will have seven stories, and he will be on the sixth story below the seventh. He will also have 300 servants who will bring him 300 plates of food in the morning and evening. The plates will be made of gold and silver, and every plate will have a type of food different from the other. He will enjoy the taste of the last plate just as he enjoyed the first. The servants will also bring him 300 glasses, and each glass will have a type of drink not found in the other. He will enjoy the last glass of drink just as he enjoyed the first. He will ask Allah, 'O my Lord, if you permit me to feed and give drink to all the people of the world, then that would not decrease my kingdom in the least bit.' The person of Paradise will also have 72 wives from the houris besides his wives from the world, and one of them will have the width of one mile." (Ahmed; Abu Ya‘la)

All perfect praise be to Allah, the Lord of the worlds. I testify that there is none worthy of worship except Allah and that Muhammad is His slave and Messenger.

The hadeeth which you mentioned was narrated by Imaam Ahmad and others, and Al-Haythami said in Majma’ Az-Zawaa'id, "It was narrated by Ahmad, and its men are trustworthy, but some of them are weak."

It appears that this hadeeth is weak, and it is not authentically reported from the Prophet because a group of scholars classified it as weak and objectionable. For instance, Shu‘ayb Al-Arna‘oot said when reviewing the Musnad, "Its chain of narrators is weak, because Shahr ibn Hawshab is weak, and the scholars criticized Sukayn ibn 'Abdul-'Azeez [who was another one of its narrators]."

Moreover, Al-Albaani classified this hadeeth as weak in As-Silsilah Adh-Da'eefah, and he ruled that it is Munkar (hadeeth related by weak narrator and which goes against an authentic hadeeth). He classified it as weak due to the narrator Shahr ibn Hawshab; he said, "This hadeeth is clearly objectionable in several parts of its context, and it is contrary to the authentic hadeeth which reads: 'He has two wives from Al-Hoor'…"

Also, Ibn Al-Qayyim was quoted to have ruled it as Munkar. His statement about it is in his book Haadi Al-Arwaah, where he said:

"The weakness of Shahr ibn Hawshab is well known, and the hadeeth is objectionable, as it contradicts authentic ahaadeeth, because someone who is of the length of sixty cubits is very unlikely to have a seat whose width is one mile. The hadeeth narrated by Al-Bukhaari and Muslim states that each person of the first group who will enter Paradise will have two wives of the houris, so how can the one in the lowest level have seventy-two? The least of the inhabitants of Paradise (in number) are the women of this world, so how can the person in the lowest level of Paradise have a group of them."

Allah knows best.