If you're looking for a new laptop to run Zwift there's a great deal at Amazon US:
Dell Inspiron 15.6" i7559-763BLK - $760
It's got a NVIDIA GeForce GTX 960M, 8 GB RAM, and a 256 GB SSD drive that can handle the graphics quite nicely on it's own or connected to your big-screen TV. The dedicated GPU really cranks out the pixels:
Nvidia GeForce GTX 960M Review
Skye