The XT8 has a focal ratio of f/5.9 so you can go as long as a 2" 41 mm 68 to 70 degree apparent field of view widefield eyepiece (assuming that your pupil dilates to 7mm) without "wasting" aperture, i.e., "stopping down" your scope. I always recommend having an eyepiece that will maximize true field of view.
If you get a 2" Barlow lens, you'll be able to use it with 1.25" and 2" eyepieces.
As mentioned, eye relief* can be an issue, especially at short focal lengths and for those who must wear eyeglasses while observing, so you may want to consider an eyepiece design with extended eye relief in the 6 to 8mm range.
* Some long focal length eyepieces can have too much eye relief.
Sic itur ad astra!
Chance favors the prepared mind.
A man is a small thing, and the night is very large and full of wonders.