It is possible to grow good tomatoes on a balcony. The main thing to keep in mind is that the exposed aspect means you will have to be vigilant about keeping the plant well watered. Also, growing in a pot means you'll have to feed it with tomato fertiliser regularly - usually weekly. Get some liquid feed like Tomorite - this means you feed as you water.
Cherry tomatoes are best if you're growing outdoors in Ireland as they ripen quicker and more reliably than large tomatoes. Something like 'Gardeners' Delight' or 'Sungold' would be good. You may still get plants for sale in your local garden centre/DIY shop, although you're reaching the end of the season for buying them.