Okay first of all you can find some rack images on stock image websites. For some great stock images, look at the free resources forums:
http://www.pixel2lif...hp?showforum=70
To make the green image do this:
Start a new document (At the size you want) - > Transparent background -> Now, with the rounded rectangle tool, make a rectangle to the size you wish - > Once you have got a rectangle that you want, - > Hit the layers blending options and hit "Gradient Overlay" alter the gradient colours to the ones you want untill your happy with the result - > Now create a new layer and call it "Racks" above the Rectangle Box layer - > Paste your rack servers into this layer - > Once you have your racks in place, right click the blending options on the layer and hit "Colour Overlay" -> Change the colour to the same colour as your boxes - > Change the opacity to around 25% - 30% So that you can still see colour but you can still see the servers. - > Add some text, add a "Select" Button of some sort then you have got your server and text.
For the lines in the middle - > Create anew layer above all layers and call it "Seperator" - > Select the "rectangle selection tool" and draw a straight 1px line down the center seprating the 2 racks - > fill the selection with a light/white green - > You should have a simple line down the middle - > deselect the line and hit the "Eraser Tool" - Click the "45" Preset, this has a nice feather touch. - > With this, begin to lightly rub out the top and the bottom untill you have a slightly faded bottom and top.
Then you should have a pretty good result, if this doesnt help, send me a PM and i will be more than happy to do it for free
Good luck