Does anyone know if there's a difference between the Gigabyte 1080 Gaming G1 and the Windforce 3x? I don't care about the backplate, but if there's a difference in cooling I would concider spending more for the G1...
Get a blower-style cooled 1080, either the Founder's Edition or one of the iterations of those. They are the recommended type of card for the Sentry, because:
1) they blow out all the hot air outside of the case
2) they are quite efficient by usually employing a vapor chamber
3) there is not enough air circulation in the GPU chamber for efficiently dissipating hot air on an open-air GPU
4) usually they come on cards with a normal sized PCB, which means they will fit without issues