I guess Lotus that is the big concern, if we do really enjoy it and can't because of the junk bike. I am hoping on riding to work most days as well. Its not real far and hopfully better then walking. So we will see.
Head down to your local Bike shop and get fitted, also check out different styles of bikes to find one you like.
Then start to scour craigslist, heck even ebay can be a decent place to look.
Since you plan to ride to work, your bike should be a little higher quality.
Kids dont care as much, and unless your wife plans to ride a lot, any bike will do ok as long as it FITS.
Key thing here is to know which bikes fit you and what you prefer, Like I said a mountain bike is going to be best unless you have serious hills or plan on mostly paved riding.
If you actually enjoy and pick up cycling your going to have more than 1 bike, its just the way it goes.
It would help if you layed out a budget on what you plan to spend on each bike and the total for all bikes.
I can shoot you some samples of what I would be going for based on that.
Buts its all very subjective and to what peopel like.