It's funny, I had a similar situation between the two; but I also was in dier need of a bye week RB, so I had to drop Miller. With that said; I'd still go with Gates. I think I'm just putting my faith back in Gates to be back more towards his old self, especially after his last performance and a bye week to rest up. It is a decent coin flip though; I think both are quality top 5, 6 TE starts.
As for your receivers; that's a tough one. I'm assuming champ bailey would be on Colston, which could limit what they could do with him. Still, Colston has been a monster in the past 3 games; and even though both players have scored a TD in each of their last 3 games, I'd stick with Colston. Again; I think it's just personal preference, since both are really good plays this week.
hope this helps; help on mine if you can : viewtopic.php?f=19&t=527593