I think that the Fraxel re:store Dual would be best for your skin type for acne scars. There are certain precautions that are needed. You need to use hydroquinone at least 4% for about 1 month prior. Sun exposure must be limited for 6 weeks prior and a couple months after.
Gentlewaves treatment has been shown in clinical papers to decrease hyperpigmentation risk. I would restart the hydroquinone about day 4 or 5 after treatment. I would avoid the highest settings on the laser and would not do treatments any closer than 6 weeks.
You can consider Retin A about 2 months prior to treatment and stopping 1 week prior. Restarting it about a week afterwards. Another option is the Fraxel re:pair. The result will probably be better, but you will need about 2, maybe 3 and there is wound care and downtime. Your risk of hyperpigmentation is greater with the re:pair, but almost always, this is temporary. Hope this helps.