Well Metchosin, you've got to take into account the setting and the location. In Borneo, the taking of the bits you suggest:

a) Wouldn't kill a man armed with a rifle outright, so you might not live to enjoy your souvenirs

b) Would be regarded as sensless mutilation, deserving of no respect at all.

Borneo and the Kalimantan on the other hand had quite a history of head hunters. Taking an enemies head in battle was to be greatly respected and in the beliefs and customs of the area, among the locals, it promised increased success and power over one's enemies for the person taking the head.