Some banks will do credit lines on investment properties, most will only do HELOCs on primary residences. 

My rationale is that if we don't like the area/job/etc, I still have a vacation rental I can use to generate some income while we decide the next area to claim as the primary residence.I also have the flexibility of purchasing more properties in CT, which I know better, and skipping the vacation market altogether in FL and sticking to just residential non vacation rentals in Orlando.

FHA means it was a primary residence.

Try to position yourself as a leader in your local market.  

Currently, I've only heard positive feedback from Huntington Bank (although I haven't actually gone forward with them yet).

Zip is fine for market analysis, but the address really threatens his position

However, this explains the lower prices for the intimate cabin setting that we are looking for.My investor wants something close to an services and attractions, hence opportunity for vacation rentals, when not used by the primary owner; but, still have the ability to provide a private intimate/eco-friendly setting for those wanting to get a way from it all.

Hi I have a primary residence mortgage 6 yrs into a 30yr conventional fixed at 4.35% and I have a rental unit 13 yrs into a 30yr FHA at 5.5%.

Hi Matt,This sounds like a question for your first position lender.  

We're hoping that we can manage to get tenants to turn over in the summer, where we can spend a couple of weeks down in DC combining a little vacation in the place with fixing things up and finding a new tenant).Of course I made some mistakes already, too, but I think I'll get away with them this time...So after getting my feet wet, I've been reading about REI, and we do have cash / equity (our primary home is just about paid off) to stuff with, so now I'm considering to get into it in a non-accidental way, and it seems more prudent to look at our local area (NH seacost), but it turns out I have little idea about the purchase/rental market here, and it doesn't seem all that easy to find out (in NoVA, at least, there's a very active market, while here prices seem to fluctuate wildly for no obvious (to me) reason.