QUOTE(itchyfingers @ Mar 4 2008, 12:34 AM)

It's extraction, lights and growing method.
I want the extraction to be silent or as close as I can get it so I think 4 inch inline fan, Carbon filter and probably acoustic ducting, although they'll be that little maybe only a metre that its pointless?
What speed controller and what other gadgets to control the lights and fans etc?
After that its lights maybe with a coolshade.
Grow method. Soil will be nice and quiet, no need for CF/PH meters. But lower yield. What quiet ideally silent hydro methods are there?
Itchy
4 Inch assuming you are using RVk's which are popular would be useless, much better off getting the 125mm or 150mm, your space sounds about the same size ruffly as my single tent, would have 125mm intake and 150mm extraction.
To monitor temps use a primair controller, will also decrease the sound of fans mainly as a result of not having them on full, keep adjusting them until you get the right temps and leave it at that, will maintain constant temps and save on leccy. The fans will have to be on 24/7 but at a much lower rate.
As for silent systems, as mentioned soil/compost or aeroponics the amazon system is very quiet, know for emense root growth and high yeilds, piss easy to use as well, they do them in 8 pot 16 and 32 for about 110.00 quid.
As for the lighting, more light more yeild, would not have anything bigger than 600w in that space though, others might know more about that, thinking 400w or 600w, will need a ballast and contactor, a contactor to stop possible fire hazzards.
As for carbon filter, get it the same size as your extraction, would avoid a 4inch fan though, totally useless my 6 inch fan bought for 5 quid produces more air than that rvk 100mm.
Not sure on amazon whether you would fit it in there, not sure of your width, you mention length, they give you the dimensions of the amazon on most sites selling them so would double check.