I went on the Ocean Nova - a Quark Ship. was fantastic! about 65 passengers, but it wasn't full. I think max is 80ish. The smaller ships can get into places the larger ones can't / don't.
Ocean Nova also had special trips that offer 'active' options - xc skiing, kayaking, ice climbing and camping. I highly recommend the additional activities. Also narrows the demographic - depending on what you are looking for.
I booked through a 3rd party and had no issues.
There was email, but i don't think internet on the boat. The various research station did have.
You'll have a FABULOUS time.