location, location, location
Circus Circus or Sahara could be decent choices for you. Yes, they are on the far end of the strip, but Circus Circus does have the built-in entertainment for the kids which is very helpful. The Sahara is right across the street, and while these two places are on the very south end of the strip, there at least are a few other things around them. (unlike Stratosphere which really is an island to itself)
You seem to be leaning heavily toward BC and IP, and if you want to be right in the middle of the strip and you've found good prices, then by all means, go for it. Simply put, there is so much hotel competition in vegas, its hard to find a bad place.
However, I've never found getting around the strip to be that difficult. If you'll have your own car, its almost a non issue in my book. But there are plenty of other transportation options, I've gotten around solely using the city bus system without any problems, plus there are other shuttles, trolleys, and even the monorail - which stops right at the Sahara, if you end up staying there.