I’m looking for an sleek integrated amp under $15k

I have Cambridge Evo 150 and can easily recommend it.  You will have some money to spare. 🎉

Sleek?  You’d be hard pressed to find something more sleek than this Devialet…

https://www.crutchfield.com/p_285220PRO/Devialet-Expert-220-Pro.html
 

Lyngdorf would also be a great choice.  Best of luck. 

@soix   Sleek not slim. That unit is pretty ugly IMO Lol 

Chord always has cool looking gear that is generally quite well regarded.   I have a Chord Mojo that sounds great and is very cool looking with multi color buttons and all … 

If you want a nice display on the unit Cambridge Naim and HiFi Rose are the go tos. The Hifi Rose integrated probably stands out if video will be part of your game.

I think Rotel just came out with something along those lines but may not be much info out there about it yet.

Oh and I would also consider NAD m33.  The room correction that comes with that can be a game changer.  
 

I went through similar choices recently and landed on the Canbridge Evo 150 and love it.  Originally I was looking at the m33 but went with the Cambridge which cost a lot less and actually had more input and output options I needed.  But the extra power of the m33 is a plus as is the room correction.