For those of you who don't manage to get hold of one of these ones from Lidl, the compressor i ended up with is not 'technically' as good as that one now that i actually look under all of the muck in the garage!, although it's performance stats aren't far off. mine is:
http://www.ebay.co.uk/itm/Warrior-50.../180980242597?
2hp
8 bar
206l/min
50L tank
and with my additional external pressure regulator/water trap, it's done me fine painting mine and as a general use air supply, although i would agree that i've probably not got enough puff for an air powered orbital sander and so while i've not got enough space for a bigger tank, the 3hp would make up a bit!
As others have said, it's a case of get what you can afford and then make the most of it!