Hardware Options
Prefab
Etsy
Premade devices are widley available on Etsy. This includes everything from handsets to solar powered “repeater” devices.
GarthV is a community contributor and makes solid devices, sold on etsy.
Amazon
If its crunch time, the Heltec V3’s available on Amazon are a good choice. Note - they dont come with a battery, and if they are bundled with one they probably dont come with a case.
If you have time to 3d print, this is a good link for a case for the heltec v3 and a battery, but YMMV regarding fitment of the battery you choose. You could also just tape it on
LillyGo T-beams
An older device with high power consumption, but will work. Has onboard GPS.
Rokland
Seed Studio (Newer device, lots of good reviews so far)
DIY
The most common DIY option right now is based off of the RAK family of boards. This spreadsheet (https://docs.google.com/spreadsheets/d/1pBLD5CCq2u9jTnDOkIY_2VyZHO8CRjrb1P8C6H_-1vI/edit?gid=0#gid=0) will detail the parts required to build.
3D print files: https://www.printables.com/model/286664-rak19003-micro-case-for-meshtastic