Here is my quick Amazon search (but there are many similar others):
Scroll down a little bit and you will see Clips and Power Supply
5A PS should be OK.
This strip does not have a dedicated White LED, only RGB but my experience with COB RGB color blending is very good (however not everyone is happy with just RGB without dedicated White).
Also you may need a wires (something like this, but make sure to chose 3 conductors):
For powering Pixelblaze you will need DC-DC downconverter.
There are very many different but for example here is one with screw terminals:
And of course you will need a Pixelblaze (chose a pre-soldered one with 3-PIN connector and what is very important - with disconnected Red Power Wire):
That wire needs to connected to the output of DC-DC converter.
Before connecting Pixelblaze to the DC-DC converter you need to tune output voltage to 5V. Otherwise Pixelblaze will be instantly damaged.
To make sure everything is working as expected my suggestion is to connect all components together before cutting a strip into pieces .
24V wires from the PS (polarity is important!) must be connected to the input of the DC-DC converter AND power injection wires of the strip. Output of the DC-DC converter (already tuned to 5V before connecting to the Pixelblaze) should be connected to the red power wire of Pixelblaze.
