My first thought was:

Hé ! Thusa ansin ! (Hé is in Dinneen as a form of "hey" or "hi".) And then I saw Bríd had it too. :-) Of course that makes it a bit more Conamara style. But I can see Labhrás's point about usage.

Building on what Cian suggested, perhaps:

Hé ! A dhuine ! A fhir agus casóig ghalánta ort ! Canathaobh go bhfuil pus ort ?

Cuirfidh mo chara miongháire ar t'aghaidh ... lena dhoirnibh.

Just trying something different from leis an gcasóig ghalánta.

I kind of like the singular lena dhorn, the implication being that he could do it in one blow.

Await further input ...

_________________
Múinteoir Gaeilge - Irish Teacher
My "specialty" is Connemara Irish, particularly Cois Fhairrge dialect, but I can also speak Ulster and Munster Irish with native-level pronunciation.
Is fearr Gaeilge ḃriste ná Béarla cliste, cinnte, aċ i ḃfad níos fearr aríst í Gaeilge ḃinn ḃeo na nGaeltaċtaí.
Gaeilge Chonnacht (GC), go háraid Gaeilge Chois Fhairrge (GCF), Gaeilic Uladh (GU), Gaelainn na Mumhan (GM), agus Gaeilge an Chaighdeáin Oifigiúil (CO).

From the same page you quoted:

". . . originally to attract attention (15c.), probably a variant of Middle English hy, hey (late 15c.) which also was an exclamation to call attention."

I believe that "Hey, you there!" is exactly that - an exclamation to call attention. Foclóir offers both "hé" and ™haigh".

Hé; Haigh; Aigh;
I think you can use any one of them, and probably a few more attention seeking words too.


Ha - is a multi-useful word in Conamara.
It can be used as:
"What?"
"yes";
A word to show you're paying attention;
Asking for confirmation like you'd say "... isn't it?" in English.
A lot like the word: "muise".

Hé ! Thusa leis an gcóta galánta [ort] ! Cén fáth [or: tuige] a bhfuil pus ort ?

New suggestion:
Bainfidh mo chara an straois sin dhíot lena dhorna.
My friend will take that smirk off your face with his fist.

The reason I changed it to "cóta" is that's what we'd use in Conamara. We only use "casóg" in Conamara for the cassock a priest wears. But both are correct for "coat" depending on dialect.