I don't think there are any arahants that are well known in the world today. If there are some they will most likely avoid being 'outed' so to speak, as it obviously leads to much more trouble than it's worth. Within my tradition I believe there are several ariyans, one of whom I've met whilst in Sri Lanka, but 95% of the Theravadin world wouldn't agree, so there you go.
That's the crux of it really. If you're an ariyan you don't want to get outed because of the trouble it causes - There would be just as many if not more disbelievers than believers and as an ariyan, your main motivation from teaching would have to be compassion, for the drive to reach arahantship once the path has been won is strong, you would just not want unnecessary distractions, the more expediently you can reach arahantship the better.
I've read Ajahn Maha Boowa's book on Ajahn Mun, and it's not my cup of tea by any stretch, I believe Ven. Boowa let his jhanas get the better of him and he fell into the unfortunate wrong view of eternalism, that much is quite clear from reading the book. I wouldn't call him enlightened and I personally doubt Ajahn Mun would have allowed his student to write such an embellished and frankly fictitious account. So no offense, but I don't think you missed out on much, besides a bit of jhanic bliss
As for Ajahn Chah - Well the Jack jury's still out. He had a lot of wisdom, and was a meditator and teacher for the ages, that much is evident. I don't know if he was an arahant, and frankly I don't care.
What you should do is focus on taking what wisdom you can find in teachings that are available, and applying them to your life and practice. You don't need to have a meditation master in the room with you in order to make progress in the Buddha's dispensation.
"For a disciple who has conviction in the Teacher's message & lives to penetrate it, what accords with the Dhamma is this:
'The Blessed One is the Teacher, I am a disciple. He is the one who knows, not I." -