I bought a flat packed kitchen from B&Q and installed it myself with very little DIY experience. I found that the units were easy to put together and pretty sturdy (especially when screwed together, to the wall and to the worktop). I also made a mobile island unit which worked out very well.
However, managing to find all the units, doors, handles, drawers, shelves, etc in the same B&Q store was impossible. I bought most parts from B&Q in Newry and Sprucefield as they seemed to be better stocked than Dublin.