If the insert has to be custom, then ModernAire may be worth contacting. I assume you have determined all the parameters you deem important relating to performance, cost, and aesthetics.

For minimal noise, use a remote (in-line or external) blower with a Fantech silencer between blower and hood assembly.

You really should do a 36" hood over a 30" range. Rangecraft is also a good source for custom hoods.

Based on "top rated product" sorts at Home Depot and Build, owners seem to like the 30" GE UVC9300SLSS insert hood. You can also see comments on Noise Level on the Lowes product webpage.

@kaseki- the insert dos not have to be custom, the hood is going to be custom made by our cabinetmaker.