My Kitchenaid has a bridge burner, but, as we've been discussing here, KA induction is annoyingly noisy. I'm used to it, and I usually can't hear it over the noise in the kitchen, but why take a chance?

LG makes a bridge burner. The LG comes with a stainless steel griddle that fits the bridge burner, at least it did in 2011.

I got mine so I could get a griddle, too, but I don't want a cast iron griddle; I want a light-weight non-stick griddle. There is no such thing for induction. If you have a good cast iron griddle, then you should be able to use it. A flat bottom will work best.

We've had a Kenmore induction cooktop for about 4 months and are very happy with it. We usually worry more about quality than price...but in this case we couldn't see any evidence that the more expensive brands were better. Be aware that size (width) varies from brand to brand, and the Kenmore takes more space than the others underneath your counter.
Also make sure you are comfortable with how the controls work - you have to slide your finger up and down to increase or decrease heat. That's a little bit fiddly, but you get used to it.
I just used the griddle on the bridge for the first time last weekend. It worked great, I just wish it was a little bit wider. And man is it heavy! We bought a cast iron frying pan too, and I just love cooking with it.
So bottom line, no regrets here.
Good luck with your decision.

Thank you. The LG was too small. I want at least 36 inches. How wide is the griddle for the bridge?

the useable space on the griddle is 7" x 15.5"