I'd suggest a menstrual cup if you're wanting to go the internal route. They generally hold up to 12 hours, and don't have the TSS and other chemical problems associated with tampons. Some popular types used in the reusable menstrual products world are also the MeLuna, Lunette, or Skoon.
I personally use reusable menstrual pads. I just prefer them in general, and I'm not worried about any potential chemicals. In reality the fibers are washed over and over and over drastically reducing chemical exposure. Not to mention they're external so about as risky as wearing panties or clothing. There's TONS of brands that offer organic fabrics as well. I make and sell my own, although my Etsy shop (Mother Grimm Moon Tides) is on hold due to some pregnancy problems. Other than my own I highly recommend Pampered Mama, Yurtcraft, and FigLeavesPads.
Reusable products have completely changed my life, I seriously LOVE them. If anyone is ever interested I'm also part of a great group on Facebook that's dedicated to reusable menstrual products.