I think the second one sounds terrible, all those mentions of 'person' do not sound good stylistically.
The problem comes because some of those nationalities aren't used to describe a person by themselves. Some of them are but there is a problem with a French, a Chinese, a Japanese, and perhaps a Nepalese.
For example,we say 'a Frenchman, not a French. We also don't say a Chinese and a Japanese, we normally say 'a Chinese person' or 'a Japanese person.' But saying these would alter ruin the style somewhat.
Here is my suggestion to re-write this:
Before this reorganization, the panel consisted of an Italian, a Belgian, a Russian, a German, an American, a Canadian, an Australian, a Ghanaian and one representative each from France, China, Japan and Nepal.
Although maybe it would bee better to be consistent and just refer to them all as countries.
Before this reorganization, the panel consisted of one representative from each of the following countries: Italy, Belgium, Russia, Germany, the United States, Canada, Australia, China, Japan, Nepal and Ghana.