Yes, they're called inserts, or sometimes built-ins. Do a search here (the one at the bottom of the page) for range hoods and you'll find out about some different brands. I've recently looked into inserts by "Best" by Broan, and Kobe.

I don't know anything about sizing a hood for an induction unit, but you can contact the range's manufacturer. For gas tops, the ballpark figure is 100 cfms per 10,000 BTUs. So a stove with a total burner output of 50,000 BTUs needs at least 500 cfm.

Other factors to consider are: baffle vs. filter design, lighting type, ease of filter cleaning, depth and width of hood. Some say get a 36" width for a 36" cooktop. Others say 3" wider on each side (42") is better. I don't think there's any official agreement on this. Some people say more important is to make sure the front of the hood extends at least to the front of the front burner, which seems to mean you might have to build it out from the back wall some.

Hope this helps -- I don't have it all figured out yet either. good luck!

There's also a faq on this forum about hoods and ventilation.