There was 2 batches of ships, the first 6 then later 9. I think one was a gift and the other was $60 million USD purchase.
According to this People's Daily article:
The patrol boats were 46-meter long and 20-meter long. I think all the PLAN FAC's are at least 60 meters in length.
Compared to the Chinese Coast Guard Type 218 patrol boat at 41 meters length (and also equipped with 1 x twin barrel gun):
I'd estimate the Cambodian patrol boats at under 200 tons in displacement. These are marine police patrol boats and really can't be classified as military assets. Even the 60 ton Israeli Super Dvora Mk.3 is more heavily armed.