I wrote my learned guru-bhai the question below. I wanted to share it with you as well as his nice reply.
"I have a question about Mahaprabhu's use of' 'na sundarim'. What is the literal translation? Is it 'Beautiful women'. I ask because although the sentiment can be applied to both genders, I wonder if a woman had composed it if she would have said, "sundaram' or is their a gender neutral form. I ask because I am writing something about this statement as it pertains to myself and I was thinking I would want to express it in writing appropriately in regards to my gender. I know it may sound like a silly point but it makes sense in the larger context of what I am writing. Any help would be appreciated."
Bhrigupada's reply:
"That is not a silly point! Literally "sundarī" means "beautiful woman", and while it is there in the singular, it really carries a plural meaning (just as dhana, jana and kavita). So yes, "beautiful women". "Sundara" in the masculine just means "beautiful, handsome, lovely" etc, but in an adjective sense, so in order to say beautiful man, you would have to add another word, sundara-purusha or something like that. So a woman would have had to find another word, such as ramaNa (lover), but unfortunately that word wouldn't fit the metre.
I hope this helps."