Is it true that lighter weight more reps tones better than heavy weight fewer reps?

There is a lot of evidence coming to light that as long as the weight lifted is repeated to VMA or more, adaptations will be simiar across rep ranges. Granted that hypertrophy still is more pronounced in the 8 to 12 rep range. But set backs and injuries are also more prevalent in the lower rep range VMAs. If hypertrophy is the main motivator (not that I would recommend such a narrow focus), then the 8 – 12 rep range to VMA will work well.

A more adaptive resistance program would be my advie.