With such similar specs youre pretty much asking which is the better graphics card. I assume you're a gamer so I really want to say the15z-j000 due to the radeon hd 8750m. The two graphics cards are very similar in performance but the gt740m beats by barely anything in RAW performance. You see...
Get the a10, it contains the 8650g graphics and works with 8750m, if you buy that version, to bring better performance. The 3.5 ghz processor and great graphics card with installing the catalyst 13.8 drivers will bring excellent performance.