We have a different structure to that of the US, with out retailers not processing so much stock due to smaller turnover. Most liquidations are done by way of auction, either on site, or through an auction house.
Check out you local auction houses, or Sunday papers for liquidation sale notifications. Forget trying to purchase through OO.com, Deals Direct or Grays if you are trying to resale.
Grays is the only one that do genuine foreclosure liquidations, but they take care of liquidation business on site 99% of the time. The other two mentioned above, while buying liquidated stock, do not pass those savings on to the customer. The stock is broken down into small lots, mostly individual lots and then sold off as new stock once more.
An interesting site to keep an eye on is Link hidden: Login to view
They don't process much, but would be my best tip for an online liquidator if you are looking to buy in bulk.