This is a more traditional gown with knotwork on the front, but if you feel like that's a little much you can look to something like the gown below...
This is a Galina gown from David's Bridal-- the only missing element is the draping on the sleeves which could easily be added to a gown like this, or not if you feel like you'd just be getting tangled up.
The key with the gown is to pick something long and flowy with nice material-- nothing overdone, just something that's beautiful in its simplicity.
You can also look for Kelly Green bridesmaids dresses (everyone looks good in Kelly Green!), add a braid to your hair OR find a horse shoe necklace for good luck! Just remember, if you're looking for luck, the horse shoe has to face upwards so your luck doesn't fall out!
For a growing selection of inspiring finds and links, check out my "Irish Wedding" board on Pinterest.