If you want to capture people then you are going to want to get a portable 3D scanner. Objects, as long as they are small enough can be captured by a desktop 3D scanner like the Matter and form for example. For people and larger objects you are going to need a portable scanner so that you can move around the object. A common hand held scanner is the Sense 3D scanner by 3D systems at about £336 or the iSense (attaches to an iPad) that is a bit more expensive at approx £435.

3D scanners differ in the level of detail that they can catch and the scan volume. For example the iSense has a depth resolution at 0.5m of 1mm and a spatial x/y resolution at 0.5m distance of 0.9mm. The other factor is the scan volume which determines the size of the object that you can scan. Again using the iSense as an example, its scan volume is a Minimum 0.2m x 0.2m x 0.2m and a maximum of 3m x 3m x 3m. Therefore you can scan a 3m^3 object.

One of your main limitation is going to be price, 3D scanners get expensive very quickly. The more expensive scanners have a better resolution and can capture more detail but this is limited by the size of the object. Scanners can capture a certain amount of data and a large object at low resolution can use up the same amount of vertices as a high resolution small object.