Rental Market in Ewing, NJ

We are under a contract to buy a 2-family house in Ewing, NJ (south of N. Olden Ave, in the Weber Park neighborhood). I've been told by the realtor that it's a better bet to convert it to a single family for a flip (she claims to have a duplex nearby for sale that gets zero interest from buyers). I was wondering if any of you know whether it's a strong rental market, in case we decide on a BRRRR rather than a flip? Trulia map shows that there are more home owners than renters there, and there are very few rental offerings in that area on the market. What other tools/websites do you suggest to use to gauge the strength of rental market?