I ordered and have tested today for the first time! I ended up ordering a single 400W flash, this one su Fotocolombo.it with a 90x60 cm lightbox. I thought I'd try this solution to begin with because I am not sure I actually need two, and I can always add others gradually. The first photographer I worked with used only one flash and they were my favorite photos. Here is a photo from today's very quick experimenting. The set needs some work on the floor and I need to play with the position of the model and the intensity of the flash a bit more before it's absolutely perfect but I am very happy with what I got at the first try. You can see a bit of the set up, and the light quickly edited. I'm shooting in a mostly white and entirely dark room and I am aiming for a strong light/shadow contrast. Thank you for your support, look forwards to playing more!