I think the TRX-4 (both types) are very beginner-friendly since most of the hard/frustrating parts are assembled for you (shocks, suspension links, micro servo cables, etc.), and all you have to do is to build the rest of the fun parts. I'm not sure about the SCX10 iii, but the SCX10 ii kit is much more involved, and the plastic Axial uses aren't very easy to work with (suspension link rod ends require quite a bit of strength to screw in, transmission housing screws are also hard to screw in), and the shocks have an issue with leaking oil. If you are interested in the SCX10 ii, the Element Enduro Builders Kit 2 is also a great option, since it offers a better value (much better shocks, smoother transmission, better plastics, overdrive capable transmission, IFS capable), and still has great aftermarket support.
For electronics, the Hobbywing 1080 ESC, Holmes Hobbies Trailmaster Sport motor (21T 550 and 27T 540 are popular), generic 30kg from eBay or Amazon, and the FS GT5 radio are popular, affordable options.