Should I build a duplex or a house for rental income?

I recently bought a city lot 50x150 in my small town. We don't have zoning laws or build permits. But want to invest in rental property. Should I build a house,duplex or a mobile home on the lot? Are the taxes higher on a duplex or a house. Are town don't have city taxes just county and school taxes. I thinking of just placing a mobile home for a quick return but if I get a duplex it might be a better return.