Make sure you create a screening policy and don't deviate from it. 

New Jersey is one of the least landlord friendly states in the country - FACT.Liberal policies are not friendly towards landlords- FACTNew Jersey is a liberal blue state - FACTI was nice in my original post.

I'm dealing strictly with the sellers themselves. 

Another huge thing to consider is laws and regulations, many times new investors will jump at Hudson county thinking the proximity to NYC is great for renting (which it is) but many of the municipalities in Hudson county have very strict landlord laws. 

Quote from @Reed Rickenbach: John - as long as you are still following strict screening criteria I agree for single family.

Don't depend on Aircover.Homeowners policy will not protect you if your renting as a STR.You need the correct STR policy to protect your property.

The building codes are pretty strict. 

I know in my area they can require it, and we are nowhere near as strict as NY. 

I am not privy to the details of that from their perspective, but I would hesitate to assume the policies are the same; I don't believe they are.

This vary heavily town to town. 20% down is great if buying strictly as investment but if you have a way of owner occupying I would explore that route and apply the 20% down to increasing value of property and instead using low money down loan.