these are all "old" processors... the quad is from Q3'09!
I would go for a model with Ivy Bridge processor. A bit faster than Sandy Bridge and less power consuming.
(But at least Sandy Bridge)
The question is how "portable" you expect it to be.
If you plug in such a big processor and a big video card then you'll need a power cord as well very quickly.
But if you want a quad core then i would say one of these:http://ark.intel.com/products/64891/Int ... o-3_60-GHz
)http://ark.intel.com/products/64889/Int ... o-3_70-GHz
or if you want the biggest one:http://ark.intel.com/products/64887/Int ... o-3_80-GHz