They may need to send a ship with more powerful sea search radar capability, and the 052B and 052C maybe more powerful than the 051B in that regard. Between the 052B and the 052C, the 052B maybe the more powerful of the two thanks to the combination of the Fregat radar and the Bandstand radar, whereas the 052C only has the Bandstand/Mineral ME style radar. The Bandstand radar can give OTH capabilities for the search. The 051B lacks both.
That also means the 054A can serve as the option. The Jiangweis won't have the same search capability.
Sending the 171 certainly defies my expectation. Does either crew on the 169 and 171 have experience in long term deployment?
I dont think China will send a FAC to the African waters. There would be some very involved logistics in preparing and sending a FAC to Africa.