While I have excellent photoshop skills not something I would do. This kind of project would take at least 2-3 hours to get a decent result. There might be a couple of folks on the forum who'd be willing to step in and help out if you can give them easy source material to work with. However here's my advice on getting the best materials from which to start. Use the best camera that you can with the highest resolution. If you have a digital SLR that will give you greater options for bracketing your settings and shooting RAW. Photograph each of the figures individually in the poses that you want turning them slightly so that you get a variety of angles from which to choose in the final composite. Shoot the photo against either a plain white seamless background or a bright color background, like neon green. You can use poster board if you don't have a backdrop which most people do not. If you have a tripod or a mono-pod it will keep your camera steady for the sharpest images especially if you are shooting without flash. Also it keeps everything at the same height. Chances are you won't be using a 3-point lighting setup, in which case try to avoid using the camera flash because it will cast hard shadows onto the background, reflect color spill and generally make it more difficult to get a razor sharp silhouette. If you set up in a outside location, such as the backyard, deck or driveway you'll get natural lighting results which will more closely match the exterior environment you're going for. As far as your background if you don't have access to a stock library it's best to do your own Google search for a photo and select the highest resolution image possible. If you can give someone those elements, they might be able to whip something up in short order. Best of luck.
