Are monks better teachers than ex-monks? It seems that most of the dharma teachers in the West are lay people, as opposed to Asia where most of the teachers are ordained monks.  Many of the western teachers were monks for a while, but decided to disrobe.  My assumption is that these teachers are not enlightened because they usually get in relationships after disrobing.

My question is, is it wise to follow these lay teachers, or is it better to wait and try to find a monk who has made a firmer commitment to the dharma?

I'm not trying to be disrespectful, it's just that it seems like the act of disrobing is sort of a rejection of Buddhist teachings.
1. There were lay Arhats

In the Buddha's time there were lay Arhats such as the rich merchant Vimalakirti of Vimalakirti Nirdesa Sutra. His knowledge was considered by the Buddha (to the discomfiture of many monks) to far surpass most monks, and equal Bodhisattvas. Thus, being lay is no reason to look down upon a teacher.

2. Having the Buddha for a teacher does not guarantee enlightenment

The Buddha was frequented by several Kings, one of them, I can't remember his name right now, and I certainly don't want to defame the wrong King, was a regular patron of the Buddha, visiting him more than once. It so happened that at one point in a succession struggle he ended up killing his own brother. So much for having the Buddha as a teacher.

On the other hand, there was a blind weaver girl who heard the Buddha speak from afar only once, and that was enough for her to begin her contemplation on death and impermanence. She died a stream entrant.

In this age of the Internet, one can be like the blind weaver girl, and listen to the great teachers of our age anytime we like. There were even people who listened to the Buddha's teachings as it was narrated by someone who had heard it from someone else who had heard it from someone else and so on, handed down several times, and still attained enlightenment.

3. Western teachers relate better to western students

There are definitely great eastern masters who have produced enlightened western students. Still,  several western students report getting very little out of the extended stays in Tibetan and Thai monasteries, other than a liking for strange food and exposure to a new culture. That's not to say it always works this way, but certainly more times than we care to admit. Especially monks who ordain as children are unfamiliar with anything other than the local culture and monastic setting, and are rather uncomfortable with foreign students.

Western teachers, lay or otherwise are often times better at relating to western students, and vice versa. That is not to say, some of them are not Dharma politicians, several of them can be that way, always saying what the student wants to hear, and presenting a false facade of calm, peace  and enlightenment, but then such teachers are everywhere, even in the East.

One Western monk's account with his Burmese teacher went as follows - he confided  his problems in attaining deep concentration to the Senior abbot, and the Abbot's only question was - "did you ever do drugs?" As a college student he had taken his share of weed, which he admitted to. That was it, the teacher decided he was unfit to be taught, and ignored him for the rest of the time he was at the monastery. The teacher's cultural perception of drugs clouded his ability to nurture the student.

I'm not discouraging you from going out to find a supremely enlightened monk to learn from, but it is the equivalent of saying, "I will not move from here until I can afford a Rolls Royce." Maybe all we need is a bicycle.