What are the most authentic narrations that mention the recitation of a thousand verses in a night resulting in a qintar of reward, and what is the best website for prophetic hadiths?

The soundest narrations concerning the qintar (though not explicitly mentioning the qintar) are what Abu Dawud narrated from Abdullah ibn Amr ibn al-Aas, who reported that the Prophet (peace and blessings of Allah be upon him) said: «Whoever stands (in prayer) with ten verses will not be recorded among the heedless. Whoever stands with a hundred verses will be recorded among the devout. And whoever stands with a thousand verses will be recorded among the muqantarūn (those given a qintar of reward).» meaning he will be given a qintar of reward.

The hadith in Al-Tabarani explicitly mentions the qintar, stating: «Whoever recites ten verses in a night, a qintar will be written for him, and a qintar is better than the world and all that is in it.» However, this hadith is lesser in authenticity than the hadith of Abu Dawud.

For the most extensive site for prophetic hadiths: Al-Maktaba Al-Shamilah. For judging hadiths: The Hadith Encyclopedia on Al-Durar Al-Saniyyah website.