I use smaller laptops to do all this and more. Netbook screens are too small for my liking but those would work too. I tend to interact with the laptop too much and having a touchscreen would annoy the crap out of me. Current laptop is an older HP/Compaq NC4200, 12" screen and it's been bulletproof. However, I'm thinking of going to a SSD (solid state drive).
I'm constantly writing comments for waypoints, importing data files, turning off/on layers, going in/out of 3D mode, etc. Often times, I'm creating routes many different ways for on road and offroad. The laptop is running Topo USA, Topo!, Topo Quads, Microsoft Streets & Trips, OBD-II diagnostic software, HAM radio freq programming software, along with the usual Microsoft Office stuff. This laptop also serves as a temp storage for picture files out of the camera SD card while we're out camping/wheeling.
Another bonus is the laptop can be used to check emails with the cell phone hotspot turned on so it's been very versatile for me.
I'm not into web based mapping tools for my mapping needs while in the vehicle, just old fashioned that way!
Good luck with your search.