They both look correct to me (including the definite articles). "Tá" is used with "ar" in superlative sentences of this type: Tá sé ar an bhfear is mó sa domhan. (He is the biggest man in the world./Is é an fear is mó sa domhan.) Tá sé ar na fir is mó sa domhan. (He is amongst/one of the biggest men in the world.)
To go off on a tangent here for a minute - "Sí-abhabha"!!! I found to my astonishment it's in "Focal.ie". I hope whoever came up with this ugly, clumsy-looking "translation" isn't being paid for his efforts :)
Séamus Ó Murċaḋa
Inis fá réim i gcéin san Iarṫar tá Dá ngoirid luċt léiġinn Tír Éireann fialṁar cáil