Exegesis:

kai idou anēr lit. ‘and behold, (there was) a man,’ nominal clause introduced by emphatic kai idou, denoting that Zacchaeus’ appearance on the scene was rather surprising.

onomati kaloumenos Zakchaios ‘named Zacchaeus,’ pleonastic since onomati and kaloumenos are synonymous.

kai autos ēn architelōnēs ‘and he was a chief tax-collector.’ autos is unemphatic.

architelōnēs (‡; not found elsewhere in Greek) ‘chief tax-collector,’ cf. on 3.12 where telōnēs is used. architelōnēs, either the head of the local telōnai, or merely higher in rank.

kai autos plousios ‘and he (was) rich,’ explicit addition of what might be presumed in the case of a chief tax-collector and preparing the way for v. 8.

Translation:

Chief tax collector, i.e. ‘one of the great/principal tax collectors,’ or, ‘the head (Bahasa Indonesia), or, the father (Medumba) of the tax collectors.’ For tax collector see on 3.12.

And rich, sometimes better appositional, ‘a rich man,’ or as a new sentence, ‘he was a rich man.’

Quoted with permission from Reiling, J. and Swellengrebel, J.L. A Handbook on the Gospel of Luke. (UBS Handbook Series). New York: UBS, 1971. For this and other handbooks for translators see here . Make sure to also consult the Handbook on the Gospel of Mark for parallel or similar verses.