I didn't know you could get a finnlight in 7 mag. Not sure of barrel length but if the length is less than 26 inches I would not touch it. Long magnums need long barrels. I have the finnlight in both 7-08 and 270 and both will put 5 shots in a quarter at 100 yards!!!
My suggestion would get a short action in a finnlight but if your heart is set on a long magnum I would get a "full sized" Sako.