Claire, Long Island is in NY.  In fact two of the 5 boroughs of NYC are on Long Island (Queens and Brooklyn).  While Long Island is a big place (over 90 miles long - hence the name),  to be geographically visiting LI, all you have to do is go 25 miles from Manhattan.  By commuter train, that's bout 30 mins, or less if you start out from Queens or Brooklyn.  We're basically a huge suburb out through Nassau County (only 26 miles wide at its widest point) made up of a multitude of small villages, towns and hamlets.  Suffolk is a bit more spread out (with Vinyards and potato and vegetable farms, not to mention  a few horse farms) but on its Western edge closest to the City it's pretty much the same as Nassau.  If you head out East to the Hamptons you have the homes and vacation homes of the rich and famous..

We're bigger than Rhode Island ( a state in its own right) and even as a small section of NY we have a bigger economy than more than half the states in the Union ).  There is money out there, but the bigger money is in Manhattan with a higher population density.  There are also a ton of providers, but mostly BP gals.  There are higher rate providers out here but they are few and usually don't answer ISO posts like the one by the OP due to a fairly aggressive LE push in the past few years.  LI is definitely a worthwhile place to visit, but be careful how and where you advertise.

When you're stuck in a hotel with no car for a few nights while working here, it's a bummer to not get a single return call from any TER Long Island leads.  A real bummer.  I'd can it to a local provider.  But not heading into the big city.  Can't wait to get home and. ........ ...