Duetto MT laser or what type of laser is most effective for my hair and skin type?

Polycystic ovarian syndrome and hypothyroidism. A mix of very coarse and fine dark brown hair. III/IV skin type with lots of PIH and darkness in inner thighs elbows underarms knees and bikini area. What's the most suitable laser hair removal machine for me to get rid of the hair as fast and as safe from burns a possible? Duetto MT or gentle laser pro? Or something else? Also 6 sessions every 6 weeks are enough to get rid of most of the hair?