I'd be using the likes of Sketchbook Pro, Paint Tool Sai, Gimp, etc for illustration work (web comics, etc) and texture work (3D mesh UV maps).
Pen ability; such as accuracy, pressure sense, and palm rejection (or optional pen only mode) are priority.

I'm on a very strict budget and I would like to keep it around 300 at maximum.

Is the Dell Latitude XT3 (i7 model with the top options) a good candidate for this?
If not, what would you recommend that's within the 300usd-ish range?