Not an answer to your questions, Gregs, but do you have an overwhelming reason for using a laptop rather than a desktop?
I just can't imagine how anyone can do photo-processing satisfactorily on a laptop, unless they couple it to a pair of 27" monitors (or, at least one).
Also, in terms of equivalent processing power, laptops seem to be very considerably more expensive than desktops.
I do, however, appreciate that personal circumstances or non-photographic computing requirements might disctate that a laptop is the answer.
I'm doing all my photo processing on a single machine which is MacBook Pro 15" retina i7 quad core 2.3 Ghz 16GB RAM 1TB SSD and use a 30" HP monitor in my office with a keyboard and a magic mouse. This works absolutely great and I have no need for a desktop machine. It's an expensive machine but it replaces both a laptop and a desktop. For me this is the ideal setup.