You see friend, it's a sad state of affairs. Even the Buddhists of this site reject your respect of our teacher on the grounds that your faith is wrong in their eyes. And if your faith is "wrong", your respect must be misplaced, is that what we are saying? What a shame!
You are not asking for much - not asking to accept your faith, not asking for their respect, just asking to accept yours and even that you are denied! What a sad sad sad world.
You know what? You actually are free to respect whoever is worthy of respect, it's up to you to measure your respect and give him a title of Prophet, or a Wise One, or an Awakened One, or whatever title you see fit.
Did Buddha teach unity or division? Buddha taught unity. Did Buddha teach "only this is right, anything else is wrong"? The Buddha taught the danger of attachment to one-sided views, and the escape from attachment to one-sided views. Whoever speaks on behalf of the Buddha in the voice of division - misrepresents the Buddha.
The message of enlightenment is the message of non-hatred, message of non-division, message of non-attachment. It is the message of peace, the message of love. The flavor is unmistakable and you can see it in any religion, whether it goes in the same depths of psychology as Buddhism or not, any true teaching is a teaching of consolidation, not quarrel of "us" vs "them".
So thank you for making this step and stretching your hand across the divide, brother. I'm confident this step is right and the history will confirm it.