so I'm guessing a family of 5, with frequent guests? You're probably going to need a fairly big grill for that.
That said, the large Weber model might be a little too small. The Member's Mark grill that is very large is has gotten fairly good reviews.
Not sure about how big you can get a VC, but there have extremely good reviews. No experience here with the Kenmore.
I'd look at the largest grill you can afford, with a MINIMUM of 3 burners.
If there is a VC that is big enough to suit your needs, I go with that. The Members Mark would be my second choice from the 3 you listed.