Downdraft Ventilation

Hi,

I am putting a cooktop on my island. I have no place to put an Over Range hood. If I want ventilation I will need to downdraft it and run it out through the side wall of my house.

Any recommendations? I am doing a complete kitchen remodel, so I do not want anything that is outrageously priced. I have seen some Gas Cooktop that have the downdraft in the center. I am wondering if that is my best bet. Also, where to buy?

*I basically cook things that are low fat and just need to boil, so I do not require a major fat filtering mechanism:)

Thanks!
Daisy