You may want to approach this the other way.
I you go to
newegg.ca for example, i see the cheapest chrome book at about 400$,
instead, do search on 8GB portable (4GB is cutting it close),
and you will see many refurbs come up 350-400$ (order by price increasing), and new coming in at 550'ish.
From a spec perspective, once you find something you want, google for linux support and peoples experiences.
You could even find out what dell models had ubuntu pre-installed, and find the windows equiv. being sold refurb.
for cheap (i would guess). With bloatware on cheap windows licenses, the cost of windows factored in is about 0$
(at least it would be on a refurb.)
I just can't help but think if you drive the search from something certified to linux (or chrome) from supplier (pre-built),
you will severely narrow your HW options.
Having said all that, I have at least twice built up a linux portable from a wiped windows one, and had video go black after
grub screen, just to have to research to add a boot time option for a intel video issue, and this type of thing, since you are
not a dev., would drive you mad. If you can find people reporting trouble free install from Linux Mint, or Ubuntu,
it should be a safe bet. You can also try to run a live DVD/CD on the machine before you buy, that would really
cement the process. You could also consider a live DVD/CD with a purchase that has full return policy.
Good luck! nice to see you attempting the Linux route.
Also, intel processors isn't a must, can run linux fine on amd (and a whole bunch more for that matter).
And I would go for 8GB ram at min.
Trouble spots are usually touch pads with multi-finger support, touch screens, and wifi module, at least a few years ago, could
still be a pain.
-tl