Hey J-Global...
As other guys have said....there is plenty for the family to do around both towns.
In Ukie....I took my niece here last spring and she loved it.
http://www.uclueletaquarium.org/
Lots of beaches to explore....places to wander around in town.....I think there is another museum or "interpretive marine center" of some kind in Tofino but I am yet to go there. May be one of the "tofinos" can confirm.
My young niece (5 at the time) from Winnipeg had an absolute blast taking a surf lesson with Surf Sister. She has been talking about it for for the past 15 months. I was worried about her being cold (in May) despite the websuit and everything but she thought it was absolutely awesome; the instructors were great too.
How old are your kids?