hi
i actually did the same thing... i think your hotel is the huge hilton resort?--if so, that's where i stayed. it's AWESOME. you'll love it. and i also took a helicopter tour of the volcanoes.
the helicopter tour i took wasn't private, so there were others in it with us. no way they were going to let us open any of the windows. so gotta shoot through the glass.
at the time i didn't have the lenses i have now. the majority of the shots were taken with an efs 18-135. i had a efs 55-250 with me, but it was really hard to use in the helicopter i remember and i didn't get too many shots with it that were not blurry. i'm better at such things now, but back them it was a real problem.
also, about getting window seats--yeah, not all seats in the helicopter were the same. i forgot how many people were with us, but some definitely had better views. we were seated in the back, and that meant the people in front blocked us. could only shoot out the sides. and even then the way the door was and stuff, there wasn't a view in all directions.
but still, was really awesome to see lava in person!
oh and one thing you should know: it is not a guarantee to see lava. apparently sometimes it flows a lot more, and sometimes not at all. it is a possibility that you will see none. just smoke and blackness. we lucked out--was flowing pretty good.
also, make sure you got a rental car. after the ride you can drive out and take shots at night from a distance. was really fun.
and there is also the trip to the top of their big mountain there. we rented an suv just for that, and i think that was probably a good idea. was really beautiful. you WILL WANT A TRIPOD there. trust me. and maek sure you accliminate at the base. i felt like throwing up when we got there.