My friend passed away 2 weeks ago. He was in the U.S. Navy and only 22 years old. He was as Irish as Irish could get and absolutely loved his heritage. I was going through our text messages from 2016 and he told me back then that he wanted to get "whatever will be, will be"/"que sera, sera" tattooed in Gaelic.

In honor of my friend, I want to make sure that I get the spelling and grammar correct for this tattoo.

Anything you can give me would be greatly appreciated. Thank you!

Sorry to hear of your loss. I would definitely get another opinion, but it seems:

would be an acceptable construction.

Where did you find that, RobertBlock78? I googled it and got no hits other than your own post. "A bheas" is used only in relative clauses, and since the second "a bheas" isn't a relative clause, it can't be used here.

An rud a bheas, beidh sé

I think "sé" is necessary, and I prefer "an rud" in this case, though there's nothing wrong with "cibé" or "pé". However, I'm not totally sure whether this would actually be said. Perhaps Bríd Mhór - our only native speaker - will comment if she sees this.

Another possibility: An rud a bhíonn i ndán, bíonn sé i ndán (What is destined is destined)