Re: Including me
#3 doesn't work for me grammatically.
I agree that #1 and #2 mean the same thing.
If you want to say something along the lines of what you thought #3 meant, you'd have to use more words. One way to say this could be I am part of a group of five men who like you. (I don't know the feelings of the other men who will be voting.)
As a matter of style, when a number starts a sentence, write it out. Five men, including me, like you. Also as a matter of style, numbers under ten are often written out as well, even when they don't start the sentence.
I'm not a teacher, but I write for a living. Please don't ask me about 2nd conditionals, but I'm a safe bet for what reads well in (American) English.