Written by The choice to either build or buy a node is up to how diy/maker you are.
Build:
access to a 3d printer and experience with electronics like arduinos is helpful. The benefit to building is cost and configurability for most nodes. You can select the components you want like battery size, solar panel, antenna, case, gps or not, cpu (mostly for power draw). Most people deploying outdoor nodes build them.
Buy:
Buying nodes is also a fine idea for quick start and certain levels of features like keyboard and screen on device. You can of course build those features diy but the cost starts to get as high as just buying.
where to look:
A great place to start for selecting nodes is on meshtastics device page
Heltec
rakwireless
B&Q
Lilygo
Seeed
BucksMesh Recommendations:
The current wisdom is for permanently powered nodes a Heltec v4, For a solar powered node a Heltec T114, for a fancy home base station the B&Q G2 station