., is there data that compares the number of syndications in the past versus those available now?

So if you do want a HELOC get it before you move out.HELOC - Pros: Fast cash, easy access, flexible; Cons: Floating rates or higher rates, less available equity as cash, short AMMO; use to take advantage of opportunities quickly then find long-term financing later, best to pay of quickly due to increased expense over other financing optionsCash Out Refi Mortgage - Pros: Excellent terms (low INT, long AMMO, higher LTV=more cash), stable/low INT rates; Con: SLOOOWWW to take out compared to HELOC, slower to reorganize/restructure or close out; generally these are good for financing other deals that are longer term and stabilized in nature. 

A normally overlooked aspect of construction/development is not comparing the opportunity cost of getting into another property in less time and less money out the gate, so keep that in mind.

Is it much harder to find renters in the suburbs compared to in the city of Boston ?

That's nothing compared to the bigger high priced cities. 

~Rough ratios allow you to compare zip codes and regions fairly quickly before you get into more property specific due diligence (taxes, insurance, utilities, etc)

The property was only appraised on a comparable basis with no comparables in the near area it under appraised.

under appraised values by the HML because of lack of comparables.

The information I am looking to obtain is how to gauge demand, pricing per night, locations to choose, and comparable properties so you can compete!

We don’t know any PMCs to recommend in the area mentioned, but since selecting the wrong PMC is usually more harmful than selecting a bad tenant, you might want to read our series about “How to Screen a PMC Better than a Tenant”:https://www.biggerpockets.com/member-blogs/3094/91877-how-to-screen-a-pmc-better-than-a-tenant-part-1-services-and-processesWe recommend you get management contracts from several PMCs and compare the services they cover and, more importantly, what they each DO NOT cover.