Hello--we are doing the Viking Venus in February--In Search of Northern Lights. Don't ask where--cause I've been scouring these boards for information on this cruise and the ports--but I found a link to this very detailed review of the ship, the ports, and excursions. It is long--but there is s much information including the names of the tour operators used.
My group have two northern lights chases booked--one each in Tromso and Alta--there really wasn't much availability through my usual operators and I didn't want to get shut out. We are still looking for wonderful and unique things to do along the way!
Safe and happy travels!!
http://www.thepreismans.com/venus_p1.htm