Grand total: $800,- (so theres $100 leftover)
There are a few choises of what to do with that $100,-
You could also get a solid state boot drive, a better GPU, a blu-ray burner or a true quad core beast.
Get the Quad Core if you multitask alot.
The Blu-ray if you might use it in the future.
And when gaming, it'll be a hard choise between the SDD and the GPU.