if you don't have enough light for corals then you definitely don't have enough for an anemone. they require super high light, pristine water and an established tank.
As far as butterfly fish, I had a Kleins and he made it for about 2-3 months and just died one day out of the blue. He was eating frozen food like a pig so that wasn't the issue but he was healthy when I went to bed and dead the next am. I choose the Kleins because based on research they are supposed to be one of the easier butterflys to keep.
i know have a copperband butterfly in my 125g reef tank and it's been a few months and he is eating and doing well. The copperbands are notoriously hard to keep too so I am on the lookout for any issues. The one I got was hand fed and qt'ed for about 3 weeks before I got him so I felt a little better about getting him. Not sure if I would recommend a butterfly to anyone though, beautiful fish but really hard to keep alive.
Good luck with your tank though!