The quote is "better to fight for something than live for nothing"

Perhaps:

Is fearr ar son ruda a throid ná gan chúis a mhaireachtáil
It's better to fight for the sake of something than to live without a cause/purpose.

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I'm not a native (or entirely fluent) speaker, so be sure to wait for confirmations/corrections, especially for tattoos.

I may be wrong but I would only use a throid and a mhaireachtáil if there was a direct object. In this case I'd say:

Is fearr troid ar son ruda ná maireachtáil gan chúis†

(†cúis with a síneadh fada, definitely, and I am not sure but I think the word following gan is lenited when on its own but unlenited when it is part of a phrase?)

Await further input ...

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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).

I'd invert an extant seanfhocal...
Is fearr deasheasamh ná drochrith.