This is our hood: Thermador 36" Masterpiece Chimney Wall Hood (HMCN36FS): http://www.thermador.com/cooking/ventilation/hmcn36fs-36-inch-masterpiece-series-pyramidal-style-chimney-wall-hood

What are you venting? An indoor grill? What is you required Make Up Air ventilation system that you have planned to work with that blower? The system of cooking production, capture and ventilation of the effluent, and the replacement of the air exhausted all has to be planned as a complete inter related SYSTEM. You cannot isolate one portion from it's connectedness to the other portions.

Thanks, we're venting an indoor gas range: http://www.thermador.com/cooking/ranges/prg304gh-30-inch-professional-series-pro-harmony-standard-depth-all-gas-range.

Without even getting too technical, I do think 1,300 CFM is overkill for a 30", 4-burner range. There is more to consider than just the amount of BTU, but as a good rule of thumb for preliminary numbers, you need 1 CFM per 100 BTU. If you have 4 x 18,000 BTU burners = 72,000 BTU => 720 CFM.

The remote blower, regardless of its size, should be quieter than the equivalent integrated unit since it will be further away from where you are standing while cooking.