Soulstealer Miss Fortune?

I have just recently gotten Miss Fortune as a new champion and the first few matches, I enjoyed the way she played. Then it got me thinking, her abilities also have some magic damage implemented along with her physical damage, so i was thinking of AP items that could benefit her, while not disturbing her regular AD items, like Hextech Gunblade and the Rageblade. I was wondering if Mejai's Soulstealer could be good on her, but I could be wrong. I want to hear from you guys as veteran members of League that have been on longer than I have, which was the middle of summer. What do you guys think?