So after taking a look at the following website, How to Use Speed Lights with Studio Softboxes and being a bit frustrated, with the hardness of my umbrella set up, i decided to get a softbox. I found a good and not so expensive one here Berlin, its 60 x 80 cm in size. Mounting the speedlight was not a hard task since I already had the clamp. In the link they talk about using an additional accessory but with the clamp seems to be good enough. Will put it for a test in the next couple of shootings. Here is a self portrait, camera in hand so nothing special, and a few picts from the setup.