Zaid Alsalami, Shaykh Dr Zaid Alsalami is an Iraqi born scholar, raised in Australia. He obtained a BA from Al-Mustafa University, Qom, and an MA from the Islamic College in London. He also obtained a PhD from... Answered 1 year ago

Bismihi ta'ala 

There is no shar'i problem at all with a Seyid/Seyidah marrying a non-Seyid/non-Seyidah. 

Islam encourages married based on the criteria of Din and Akhlaq. Please review Ayatullah al-Udhma Seyid al-Sistani's advice to the youth, where he mentions this as well:

https://www.sistani.org/english/archive/25240/

Wassalam