Plynnt - I would heartily recommend you read the information in the following link
http://mikeaurelius.wordpress.com/ventilation-primer/
as well as the other two Art Glass Answers links I posted earlier. The link, above, will walk you through how to decide what fan size is right for the size hood you want. From what I've read here in LE and elsewhere, most folks pick the size hood they want to work under and then pick the fan. Seems like 30" wide by 24" above the work surface is fairly common, but everyone has different preferences or space limitations.
I personally wouldn't buy any fan for which the cfm vs static pressure wasn't available. Some fans, although seemingly beefy, can die under the slightest static pressure (ie 'back pressure' caused by ventilation duct bends, long runs, or flexible ducting). As Yeepers notes, duct booster fans are an example. They aren't designed to be the primary fan in a ventilation system, anyway, so it's not surprising - I've heard they can lose as much as half their cfm under very little static pressure.
I didn't see any cfm vs static pressure for the fan you asked about, so I would assume that the numbers shown are the 'free air' or zero static pressure values. Might be ok if you vent directly outside with no bends and no flex ducting (flex ducting is awful - can absolutely kill a fan's performance....), but you take a risk of having far less output than expected if you have any kind of long or complicated ducting to get the fumes outside.
Like Christina, I've wondered how to verify whether my vent system is giving me the draw I calculate I need. I've been working on one with a tricky fan installation issue, so I've been testing it by timing how long it takes the smoke from a burnt paper towel to travel from my torch flame to the exhaust duct opening in my hood. I compare that to the time I expect it to take (I divide the volume of my hood by the cfm I'm shooting for). If it takes the smoke longer than that, then I'm not getting the draw I want. I'm building a barley box style hood, by the way, so predicting how fast the smoke should be exhausted is pretty straight forward.
Linda