In looking back on some of the easiest kits I've put together over the years, Monogram stands out. I'm a hot rod/street rod/muscle car builder, so I'd suggest the '29 Ford RPU, '70 Chevelle, or '53 Chevy. Perhaps as his 5th/6th model(s) - an AMT '66 Nova Pro Street or Revell '32 Ford Coupe/Roadster. These are all good candidates due to ease of assembly and are really brought to life by simple detail methods - dry brushing, washes, flat/semi-gloss/gloss combinations, sanding tire treads, etc.