Help selecting a laptop

I am looking to buy a new laptop to use for workouts. The requirements are as follows:

Recommended system requirements

Processor Quad core 3.0 Ghz, Intel i7
Min. memory 8 GB
Free disk space 20 GB
Graphics card DirectX9 compatible 3D card with 1 GB
Various 1 free USB port, DVD/Blu-ray player
Operating system Windows 7 (64-bit) or Windows 8 (64-bit)


Minimum system requirements

Processor Intel i3 processor or AMD equivalent
Min. memory 4 GB
Free disk space 15 GB
Graphics card DirectX9 compatible 3D card with 512 MB
Various 1 free USB port, DVD player
Operating system Vista or Windows 7


This is the product that I have:

http://www.tacx.com/en/products/software/tacx-trainer-software-4-advanced

and

http://www.tacx.com/en/products/trainers/vortex-smart

I am on a budget of about $600 so any suggestions are appreciated.

Thanks,