Bro, you have 3 options,
B6T
BPT180
BPD210
all are rally proven engines, the best on is offcourse the BPD ! but you need to go around, because hafkat shop like to sent them to Aus/NZ, a lot off fans over there that are willing to pay bigbucks for BPD, 210hp !
I think theres no problem to find BPT & B6T.
ZTH gots its own mazda/ford thread, go check it out