When it comes to property taxes, don't go by county. Go by the individual towns.
For example, Fairfield in Essex County, has a lower effective tax rate (1.933%) than almost every town in Morris County. Parsippany is 3.03%.
So a $600,000 home in Fairfield (Essex County) will have property taxes around $12k.
While a $600,000 home in Parsippany (Morris County) will have property taxes around $18K
West Orange at 4% is insane though. Your $600,000 house in West Orange will have property taxes of $24k.
Maybe look into Florham Park. At 1.56%, a $600,000 house will have property taxes of less than $10K. Only $600,000 will limit your choice of homes in Florham Park, but they do have good schools.
There are several sites where you can look up the effective property tax rates. "Effective" property tax rates are more accurate than property tax rates, because the effective property tax rates take into account the multiplier that the town uses to decide how much you have to pay.
Here is one site that I like, because of the map they use at the bottom:
https://joeshimkus.com/NJ-Tax-Rates-Morris-County.aspx
They get their numbers right off of the official state of NJ website, which can be found here:
https://www.state.nj.us/treasury/tax...20taxrates.pdf