That is a great deal!
Regarding spec I would rahter go with the 8GB of RAM now also in a discount for $619 (and FS).
Most probably you could get another discount with your corporate perks discount.
http://dealmacher.com/seller/lenovo-thinkpad-z50/
I agree with turkey3_scracth.
It should definitely be OK with your needs.
I saw one on a deal today and got it for myself Z50 Deal.
I think it's a reasonable deal for the components.