Photoshop experts to enhance a studio photo

We need to turn a studio photo into our promotional photo. This involves a baseline photo of 9 people in various poses around a couch, however, we need to replace 3 of the people with images taken from 2 other similar shots (from the same session) in order to produce the resultant base image. From there we need you to adjust the lighting and exposure (to bring consistency to all people in the photo), some background and equipment removal as well as styling and various touch ups of the people in the photo including teeth whitening, blemish removal, general complexion and skin smoothing and some minor body shape modification. Once this raw photo has been produced and enhanced, we require a couple of versions including a version that is stylised to look "glamourous and chic". As well as another version that is stylised with some low level posterisation to look somewhat illustrated. We will be expecting you to bring your artistic expertise to guide us and help us make this photo as impressive as possible without needing us to be specific about every step required. It is acceptable/desired that the people in the photo look "photoshopped". This is a promo photo and we want it to look very well produced and almost "unrealistic". You don't need to hide that it has been enhanced. From a deliverable perspective, we will require the resultant photoshop files with at least the floor and background as separate layers. I've uploaded the images for reference The photo [login to view URL] is the base photo we are starting with. We need to replace the person on the back left (white jacket and tie) and the person in the middle rear (pink jacket) with their images from Dsc-5371. This also involves including the guitar in dsc-5371 The person on the rear right (red jacket) should be replaced by their image in dsc_5360. In dsc_5376, the girl on the couch in the green dress needs to have the size of her right calf reduced to reduce the effect of it squeezing against the couch. The lighting stand and light that is visible on the right hand side should be removed. The background from the tiles up should be removed (including the shadows cast on it) and replaced with a uniform background. This should be a separate layer that we can use to change the background at a later time if needed.