Shoutbox

Best I can think of is a Lenovo X230 or an X1 Carbon

No dGPU though, and around 13",

Beyond that, I'd say like a Samsung Series 9 but then you get crappy display etc.

If HD4000 is good enough for you (consider this, it may be), then go for what I initially suggested.

Beyond that, admit defeat, get a ThinkPad .