I agree with you - I think Opium (the women's) smells very much like JHL.
Of course, it is common knowledge here on Basenotes that:
1. Estee Lauder's fragrance for women, Cinnabar was their version of Opium. A dazzling, aldehyde-sparkling oriental.
2. Both JHL and Cinnabar smell VERY MUCH ALIKE. Many guys have done side-by-side tests and their opinion is JHL is the EdT version and Cinnabar is the EdP version of the same scent.
To answer your question, I say wear Opium if you feel comfortable doing so. You might want to try different formulations. Maybe the Eau de Parfum will wear more comfortably on you, than the Eau de Toilette? Maybe the parfum (which is the most expensive option) will smell better? Try all of them.
As far as layering with something - well, JHL has a much more grounded and woody base. So perhaps any essential oil derived from a wood might give you that base note that will make Opium a little more 'butch' for you.
One more word of advice: Try spraying Opium on and waiting about 30 - 45 minutes before leaving the house. I think you'll see the middle and base notes are more woody.