Check that the panel can handle VGA input at 50Hz otherwise it won't without extra help. From the brochure it looks like it can't - in which case you need to get a framerate converter between the panel and the BS2 (A CP251F from Lektropacks)
Secondly you won't be able to switch the panel on or off from the BS2 without another box (Lintronic) so you only need the VGA cable from the BS2 to the screen and with the framerate converter it should be OK.
If you want HD, you connect the STB directly to the screen - and if it is SkyHD, you'll have to connect it via a HDMI-DVI cable (DVI on panel side)