In order to avoid blinding the crowd I would say up-lighting (i.e. have the light on the floor behind you shining upwards). This will keep direct beams out of their faces.
Lights come roughly in two flavors, spots and floods. Spots are – as the name suggests – used for small area illumination, like the nice circle on an artist on stage. Floods have a much broader angle and are used to color areas of walls, ceilings or floors.
Shouldn’t be too hard to rent one of each (get LED because regular lighting gets way too warm to have close behind you heheheh) and try them. Take someone to shoot some vids while you are experimenting and you will soon find what works best for your purpose.
.
