This may or may not be helpful, but:
1. I think you'll find the majority of niche is unisex, including many of the niche favorites on the male board. There is no need to limit yourself to the small few with "pour homme" on the bottle!
2. You're likely to get a huge difference of opinion on what are the best male niche fragrances, and lots of suggestions, so prepare to do a ton of sampling.
Perhaps it would help to start by asking what your current favorites are...?