That could be a hard goal to achieve without someone willing to take the chance on you. Insurance requirements are rough and the accident/incident rates are considerably higher the land operations. Best time would be in a 185/206/Caravan or a single engine Otter if you were holding out for employment opportunities in the Seattle/Alaska region.
There is a Part 121 Twin Otter operation down in the Carib, that uses co-pilots. Might be a good place to get your feet wet
I think they are called Seaborne?