gyn onc is 4 years...so you're looking at 4 years of residency plus an additional 4 years fellowship. most other fellowships are 3 years if i'm not mistaken, i.e., REI, MFM, although i am not sure about others like uro gyn...
i think the malpractice insurance depends on what fellowship you do...for example, maternal-fetal medicine will be expected to have a much higher malpractice insurance premium compared to REI...