Hey Eduardo Magana ! Any updates on this?
A few things to know and expect with this:
1. You should hire an attorney to represent you for this matter as it is much more complex than just going to the board for a variance on your own. It can be costly either way. You will likely need a planner as well regarding traffic, parking, water diversion, sewer impact, ingress/egress, etc.
2. Every diversion against code or "best use" of the property vs existing homes/permitted use reduces your odds of approval.
3. Lot size is highly relevant with any use and our opinions are irrelevant. The local laws are what they are and it's what you will encounter in any town/city. For example in my town we need " 1 and 1/2 parking spots per unit" so 3 spots for a 2-family home.
4. Your neighbors have no say in your tenant selection, it's up to you as a good LL to screen properly.
I would consult a lawyer and go for a high quality 2-family rental if anything.