There are a lot of factors to consider with LED lighting.

the colour, Warm white or cold white, or multi coloured?
the size of the LED's, the density of the LED's on the strip, both of these factors will effect the size of the power supply you will need. ie: Voltage, currant and as a result Wattage/power.

For a whole room I'd suggest, multiple strips and multiple power supplies. Strips can be purchased fairly cheaply off eBay, as can connectors and other elements to make the installation neater.

the packs that can be bought at retail, bunnings, Aldi, Ikea etc are very expensive. LED's are very cheap to manufacture.

Make sure you get a power supply that meets Australian standards.

I'm still putting mine together but I want to angle the LED's so they are facing into the cabinet from the front, hopefully reducing some light bleed.

I'll post some more thoughts and details later if you are interested.