@Andrew B. I have done a few of these myself and it’s fairly straight forward. Yes, I got the rebates and overall a simple process. For replacing main HVAC I had the contracting company complete the necessary forms and sent back to me for submission.
No need to have a home energy assessment in my opinion if you know the basics of the building envelope concept. Each year in NJ the rebates/criteria seem to be a bit different.
Ultimately, take a look at cost/benefit since you may need to spend a bit more for energy efficient units that will save your tenants money in the end and not you. This weekend starts Memorial Day so plenty of sales happening. You will also spend quite a bit of time researching particular units/models eligible for the rebates and then find a local vendor or supplier for those models.
However, I am a fan of reducing waste and energy to lessen the environmental impact in a way that balances the investment, but that’s my personal approach.
Lastly, make sure you have every detail 100% complete and required for the rebates and have copies, just in case NJ says they “have no record” of it and you can resubmit.