What would be the best course of action to sue them for non-payment? 

Short of selling my entire portfolio, the liquid capital for the down-payment remains unattainable. 

Find Brandon's videos on YouTube for the "four square" method of analyzing homes and practice.

I've been reading more about subject to and here's what I've learned:-Good for sellers who are off market-Have low to no equity-Have a mortgage with a low interest rate (less than 5%)-Be absentee or out of state (vacant property, or have a tenant)The buyer would then take over the mortgage payments, and have the seller sign the deed over to the buyer.

Social security number is definitely not required for non-payment for eviction in NJ.

Interest only loans allows them to get a goal profit of $500-$600 per month per property.3) Each acquisition would require 20-25% down at an 80-100K purchase price. 4) Closing costs, and the Eric Spofford turn-key transaction fee of 10K would be in addition to the down payment and were not included for the purposes of calculating the cash-on-cash return.

Quote from @Jimmy Rojas: Thanks for the reply, i think it may not be worth it after all, may I ask did you use a calculation app to come up with the mostly payments, if so, care to share it with me.One more thing.

I know what seller financing would involve in regards to me (the buyer) having to pay a interest rate set by the seller and the monthly payments also set by seller.But what are the benefits of seller financing a property?

Credibility Package - $7,800 reduced to $5,800 if you sign up right away. 2 to 3-month payment plans available. 

Most who try to replace their W2 income invest in less sustainable investment methods: investing in lower tier neighborhoods that cash flow well in spreadsheets or flipping homes.