Laptop choice. Real estate vs Screen Quality

Hello I am about to purchase a Vortex III laptop for photo editing, with SSD, extra hard drive and 16gb ram.

There are two sized models of the same brand. I don't want a desktop because of space issues and I am unlikely to take it out, but it remains a possibility, depending on the photography.
I am also planning to get an external monitor at some point in the future.

I need to make a choice between the two sized options, that is based on the extra real estate of a 17" vs the better screen quality of the 15":

17" version with a AUO Matte, 72% gamut widescreen,which is supposed to be great screen. (because of the size I can also have a DVD drive) £1727
or
15" with an excellent screen, AUO Matte 95% widescreen, (no DVD drive) £1639. The colour reproduction is supposed to be superb, based on reviews.

Seeing as I intend to get a 24" plus sized monitor in the future and I could purchase an external DVD drive sometime, what of the two options would you recommend for photo editing?

Do I need a DVD drive for screen calibration software?

Thank you,

D.