Well...I can't recommend anything in original Irish suitable for a beginner, although I've seen a number of possibilities. I just haven't purchased anything! I do recommend An Prionsa Beag, which I have purchased, and it is a lot of fun to read. In general it follows the English translation fairly closely, but the Irish idioms are faithfully executed.
As to other possibilities, might I recommend that you look around on www.leabhar.com as they feature a number of books for different levels of Irish learners. They also include some comic books! One that looks intriguing is called An Tóraíocht which is a comic-book retelling of Tóraíocht Diarmad agus Grainne. I have a published version of the story that a friend gave me when I was in Ireland in the '70s, and it is a challenge to read. The comic version, based on the panels they show on their website, looks much simplified as a lot of the actions are visualized so you're mostly reading just dialog. Anyway, when you go to their Siopa/Shop link, they break down all their available offerings into categories, such as Children and Beginners, Teens and Adults, Comics, etc. I suspect you can probably find something of interest that would be useful.
Disclaimer: I am not in any way affiliated with www.leabhar.com or Cló Mhaigh Eo so I cannot vouch for them, and on the other hand I'm not remunerated in any way either. It does appear to me to be a good resource for getting Irish literature in appropriate levels.
Dale D