It takes most people new to electronics assembly 6-10 hours for their first time assembly of a PCBv3 ECU, a bit less for a PCB2.2, and the stimulator (which you should do first) is very simple and takes maybe an hour to assemble for a first-timer. Check out Youtube for some good solder technique videos like this one. We do often recommend you build your own MegaSquirt at least the first time around as it will familiarize you with the hardware particularly if mods are going to be required for your implementation. This way it’s not all new to you when you get to the mods needed for your setup.
If you can follow step-by-step instructions, or paint by numbers, YOU can build a MegaSquirt!
Note we also offer all of our systems fully assembled if you’d prefer to skip the assembly phase.