Designing Kitchens and Bathrooms - Kitchen wall hood vent, (best one and why)

I am remodeling our kitchen and want a very efficient, effective and quiet hood vent that will move up to 600 cfm of air and cost around $1,000. or less. I will vent to the outside. It would be helpful to hear ideas about roof vents. Does anyone have suggestions and reasons for those recommendations?

I have installed a couple of roof mounted vent fans, which had a rating of 750 cfm. They were quiet in the kitchen, but IMO, anything above 300 cfm's will evacuate your heat and cooling as well, causing your heat pump/AC/heater to work harder. In the area of your stove, unless it is commercial grade, you only need to exchange the air immediately in the cubicle several times a minute.
I also had to custom build a venthood, since it only came with the roof mounted fan, and the under counter unit with damper and heat lamps (for keeping food warm).

Larry, Thanks for your time and info. I have a 1000 cu ft kitchen area and a 4 burner Viking range with 15000 btu / burner or 60,000 btu total. Your point of vent extracting heating and cooling from my house-(2500sq ft) is something I had overlooked. I think I should look for a vent that has multiple speeds so as to have control over that aspect of hvac operation.
Last night I was looking around on internet and found a vent hood that is relatively quiet(1-3.9)scones. The most quiet one I could find for around $1000. I am not ready for a roof mounted air extractor yet. I do not know how loud a scone is. All that Google could provide was the sounds of ooh's and aah's or the slight crunch of that little biscuit when properly eaten. I'm not ready for that yet.
In my mind this hood should have had a scoop feature for more effective contaminated air capture. By scoop I am referring to a perimeter that is 2-4 inches below the filter screen and provides a hot air dam. But to my surprise this model was flat across the bottom as are many. Am I off the right track in wanting an "air dam"?

That 600 cfm fan you talk about will take out about 1 .5 ton of your AC in the home . If you look around when we put vent fans in like that we also put a fan in the will blow air down into the room also lots of time it comes out in the heat dam you talked about. Yes you are right the filters should be up in the hood also dont forget you need a grease gutter built into the edge of the hood all around

I purchased Broan Elite series hardware and built my own custom hood. I am still working on it actually. This stuff was actually intended for a wall mount unit but I have an island cooktop and adapted it for that purpose.

I purchased this roof top exterrior blower unit 900cfm ramp up and down variable speed which also required the 332KR rough in kit. Because the fan is unlimited variable speed I can set it at whatever. The unit is extremely quiet unless if I crank it all the way up. On its highest setting it sucks harder than a $2 ho. It is a 10" round duct. Being in Hawaii I can actually almost use the thing as a vent at night to suck out the hot air and suck in cool outside air via open windows. ;)
http://www.broan.com/display/router.asp?ProductID=1253

I purchased this Custom Power Pack/Power Module Pro-Style Insert
http://www.broan.com/display/router.asp?ProductID=100125

Picked up this liner which gives the 4" from the bottom lip to the baffles.
http://www.broan.com/display/router.asp?ProductID=100135

I also went with the pro-style baffles instead of using the supplied filters
http://www.broan.com/display/router.asp?ProductID=1333

Overall I paid $1400 shipped to Hawaii. Shipping was about $190. Still cheapest way to get it to Hawaii. Cheaper even then ordering from a local vendor.

Here is the Hood set up. I cut the hole off centered so it needs a patch, plus I will run crown around the top. I also need to do a little more trim work and then stain it. Hope this helps.
http://www.mustangmods.com/ims/u/1063/9183/158224.jpg
http://www.mustangmods.com/ims/u/1063/9183/160834.jpg
http://www.mustangmods.com/ims/u/1063/9183/164754.jpg
http://www.mustangmods.com/ims/u/1063/9183/164753.jpg
http://www.mustangmods.com/ims/u/1063/9183/162047.jpg