I have an Alpine IVA-D901J touchscreen, along with an Alpine RUX-C701 Multimedia Manager and a PXA-H701 surround sound processor.
That is about all you need to watch DVDs with surround sound in the car.
300 quid for the lot. 115 for the Head Unit.
I also have a little 45W Alpine Center Channel Amp and a Navigation System NVE-N555SS I will throw in if you buy the whole lot. I am sure you will find the Navigation System very useful if you ever drive your GT-R to Japan.
All this kit is in good working order, hardly any marks on the displays/panels and comes with LOTS of cables I carefully removed. No use to me as I just have a basic Kenwood and a CD changer, although I am keeping the Alpine active Subwoofer for myself...
It all came out of an Evo from Japan, sorry no manuals or orginal boxes included.