The route via 95, down to and through Needles is a good road, kind of like a roller coaster in places but not at all bad. When you come to #62 you'll take a right, but if your low on gas, a little bypass to Parker will get you gas about 30cents cheaper. From that intersection to 29 you really isolated but its a nice road. 
Amboy is probably a little shorter and way more isolated if that is possible. And taking 247 out of Barstow is a great road and hits more towns, and not quite as isolated but a lot of back tracking to 29.