The idea of a green screen is to remove the background using a chroma-keyer. This is necessary in movie making, since you can't isolate the foreground frame-by-frame.
In photography, it's actually more cumbersome to use a green-screen and chroma-keyer than it is to simply cut out the person, using photoshop.
There are a number of programs that allow you to cut out the person from a picture and none of them require a green screen, since you are not using a chroma-keyer.
The challenge in a photo is to make the lighting appear natural..or rather, consistent with the new replaced background.
Photoshop has a feature that allow you to merge two layers so that the top-layer has the same lighting as the rear layer.
There are a number of good photoshop tutorial sites out there that can show you - step-by-step - how to do all of this. You can Google it, but here are a few sites I use:
So, you can possibly save yourself some floor space and some studio lights and instead do it all on your PC.
Whatever solution you end up using, it would be great if you could share a few examples (or more!) with us