Dust extraction systems

Im looking at spec-ing some dust extraction systems at the moment for a small workshop, measuring about 8m x 10m. Can anyone advise on the most appropriate systems?
Will be carrying out composite assembly operations such as drilling primarily and some trimming – may look to do some grinding/sanding also. I think the down-draught option and these guys look good: http://www.airbench.com/ I cant imagine we will be doing massive amounts of grinding and I would imagine there wouldn’t need to be too many filter changes. We have some fume extraction in there at the moment but it is pitiful to be honest, insufficient power and filters. It just seems like the down-draught is a more flexible option with less hassle of continuously having to move flexible extraction arms, etc.
Any thoughts? Thanks v much