For a 2x4 mile commute it makes little difference which style you use. Look for some useful features:
Gears low enough for your hills.
Threaded eyelets for rack and fenders.
Clearance for your widest winter tyres, 32mm or maybe a little wider.
You dont need suspension.

The kind of bike illustrated by Trek 7.5 FX is probably a good all rounder. You can find them in most brands and since they are all made from nice Taiwanese frames with Shimano kit, the brand makes little difference.
I would pick my bike shop first then see what brands they do. You will need advice on the correct size and help fitting accessories such as fender, rack, lights, bags and some kit such as helmet, lock, repair kit.