As long as it has low, high, and auto settings, the make isn't that important. I've got huge Prima slow cooker and keep meaning to invest in a smaller model - your Breville from Argos looks like a very good buy Auntie.
There are so many slow cooker recipes on the net it's not worth buying a cookbook, and most recipes can easily be adapted for slow cooking; meat loaf, pot roast, boiled (salt) beef and carrots with fluffy dumplings, ratatouille, veggy casseroles, pie fillings, tagines, curries, etc. I like to cook porridge overnight in winter - there's something magical about tucking into a hot breakfast with no effort.
I've got a Prima breadmaker (one owner, barely used, any takers?) but I'm reliably informed that the best make is Panasonic.
I'm a kitchen gadget whore; anyone got a Remoska? I've been trying to convince myself for the past few years that I can live without one, but I'm in serious danger of succombing to the hype.