According to our hadiths, the following is recommended:
-In the 8th rak’a of Salat al-Layl to recite Sura al-Insaan
-In the 1st and 2nd rak’as to recite Sura Ikhlaas 30 times
-In the Shaf’a prayer, to recite Sura Naas and Sura Falaq
In the Watr prayer, to recite 3x Ikhlaas then Falaq and Naas
Yes the Prophet (s) would recite long Surahs because he would spend most of the night standing on his feet.
You may see this video for further details: