Safe travels and I hope you have a great time.
You'll find proper ones in most jewellers. Certainly that's the case in Dublin. There are various options on the type of metal used which will directly correlate with pricing.
I know that's very broad but at least stick with a jeweller is my advice. They're very popular with tourists and Galway's a big tourist destination so you should have plenty of choice.
If you can swing a trip to the Arran islands which are just off the coast I would highly recommend it. It's about 35 minutes by regular ferry. Definitely one of my favourite destinations, especially in the off season.
Superb bar just at the harbour and one of my absolute favourites about a twenty minute walk outside the town. Singing, late service etc.
Observe and blend ;)