Nekro, there's no Sony USA, CAN, UK, AUS site that supplies any better links than you've found. Sony used to be better than this - now they're as bad as HP.
The worst thing is that the Motherboard Chipset Drivers can be critical, and there's little chance to discover those without trying any variety of other SVE151xxxx series. That's probably what I'd do next... hopefully, the Wrong Drivers will simply refuse to install - not render the machine unbootable.
(You will definitely want to learn about SAFE MODE, by the way, on Win 8.)
If this indeed has the Radeon Video and is an AMD chipset, I would probably go to AMD and install their AUTO-DETECT software and see if they can deduce what you need.
This might give you Motherboard Chipset, certainly Video, HDMI and perhaps Audio. Of course, you must have the LAN services functioning first. (If I couldn't get the LAN port to function, then I'd plug in a Wireless USB and use that, at least temporarily.)
(This is the second Sony in Spain that has some model-number that Sony no longer acknowledges. Does Sony have something against Spain? Is this that Black Ship thing again?!!)