What i want to achieve is multiple flashes in one long exposure photo graph.

so what i was thinking of is a setup where the camera takes a 20 sec long exposure shot and I manually fire flash 5 times pointing at 5 different points in the picture or stand in the picture at 5 different locations and trigger flash manually to highlight the subject. (Cheap Stroboscopic Effect i guess). so i am moving the flash from one place to another (off camera).

Do i need a special flash unit or any will do and apart from a Flash unit what else do i need to achieve this. triggers? etc.

I am a newbie to simpler the better