I chose to composite in Photoshop for several reasons,
I find editting easier in PS
Its all embedded, no loosing files
Less resources intesive, with Houdini open
To add a bit of realism to my image a used some free CREATIVE COMMONS stock images from DeviantArt and Mayang.
Originally i wanted to create a cool background for the image in PS but just did not have the time to do it.