The previous verse demonstrates how Jesus developed the humor in his lines. This line continues with that method.  The primary humorous word from the earlier verse translated as "pluck out" and "gouge out" here. The verb is only used twice by Jesus, in these two verses, to conflate the ideas of "take out" and "choose." This may be a humorous reference to Lev 19:14 "Thou shalt not curse the deaf, nor put a stumblingblock before the blind, but shalt fear thy God: I am the LORD."

Jesus maintains the more complex phrase order (when compared to the Sermon) of the previous verse here because repetition is a key part of his humor. Where in the previous verse, he was able to play with Greek sound-alike words, here he plays with one funny word--one-eye-- and one funny image, being more "beautiful" with one-eye than two. 

The word "having" has as its object an infinitive, "to be to cast/to be thrown." With an infinitive object, is means "having the means to be tossed." When its object is an infinitive verb, it means "to have the means or power," or "to be able" not "it must" as in English. 

Jesus also makes it clear that "the fire, the perpetual one" that he describes in the previous verse is the always burning trash heap outside of Jerusalem.