How much do you want to spend?
Does the screen being in color matter?
Are there any applications that you know you must have access to?
m_struct said:
I have used iPads in the past and liked the interface but not the compatibility with PC.
Can you elaborate on this a bit more, any secondary device is going to rely on some mechanism to transfer files to the main work machine. These days Google Drive, Microsoft Onedrive, and Apple's iCloud pretty much remove the need to ever directly attach the device to the main machine anymore to transfer files.
Some options:
iPad Pro or Mini with Apple Pencil using Concepts, Onenote and Office365/Onedrive (IOS, need to rely on synching files using Onedrive or one of the other file hosting services)
Microsoft Surface Pro (current gen) with Krita, Onenote, Drawboard PDF, and Office365/Onedrive. (Full windows, Onedrive or local network for synhcing files, the camera is garbage so keep that in mind for the site visit aspect. The surface go has had lackluster benchmarks so would suggest an older gen pro over the go)
Samsung S7 FE with Concepts, Onenote, Office365/Onedrive (Android, need to rely on synching files using Onedrive or one of the other file hosting services)
Remarkable or similar e-ink device (Remarkable just changed their business model and added subscription costs so maybe steer clear of that one, seriously long battery life but no camera and usually proprietary note file format)
My Personal Open Source Structural Applications:
Open Source Structural GitHub Group: