For reading without glare, the kindle, kindle paper white or kindle keyboard is best because it has the e-ink technology that eliminates glare in bright light. The e-ink technology is not compatible with the " tablet" technology used in the kindle fire. You can still read with the kindle fire, but will get glare in bright light and can be more tiring on the eyes during a long reading session.
Since you want to read, do email, and watch videos, you might be happier with the kindle fire or an iPad. The tablets do a better job with Internet activities such as email and video.
If money is not a problem, I would go for a basic kindle (about $80) for reading and a fire or other tablet for the email and videos. Otherwise, it is a trade off between a better reading experience or a better email/ video experience. My info came from a kindle rep.