The M2000 is not a *bad* card. Its just not an elitest card. I work on an M2000M (lesser performing than an M2000) every single day, and it runs GREAT, with all of the graphics features on and set max. I just cant walk around a 1GB model in enscape, in real time.
I would say for JUST working in revit, you could go to the K620 and be fine... Its just going to not be as great at the realtime render VR type stuff.
I think you would have to be crazy to run on an integrated GFX card, skylake or not. But thats just me.
Also, switching the RAM from 16x4 to 8x4, and then buying your RAM later should you need an upgrade, saves you about 250 bucks on the machine. Worth it, to me.