my first season with cardiff I got kakuta on loan, nicola mingazzini, michael ball and fabian carini all on frees.
Although I probably didn't need michael ball I would strongly recommend the other 3. Played a creative 4-4-1-1 with kakuta just behind bothroyd and won the championship, however it was a close run thing so you could probably employ a better formation than me and get better results.
Fabian Carini I consider an absolute must though, my first choice keeper for years and whats better is that he was free!