Nex6 plus sigma 19mm
To get the Nex6 with a single lens is genius ! and the sigma 19 is certainly a very good lens.
You might compare your buy with the new Ricoh GR
it costs 700 $. But you get a system camera with exchangable optics and viewfinder. The 19 mm sigma is equivalent to a 28 mm for a 35 mm film camra. So it is really wide angle. I would rush out and by the sigma 30 also. This corresponds to 45 mm and is much better for people, portraits, etc. Further it is an extraordinary sharp lens.
I own a Nex6 myself. I use many legacy primes, but I have also the 16-50 sony zoom, and a sony 12 mm, and the sigma 30.