What size components should I use with ATF-55143

I have heard to use 0402 component package size for ATF-55143 at 2.4 GHz, but what 0402 would you think they are referring to imperial, or metric? I wanted to look up the size of 0402 package, but this is what they give me: https://www.google.com/search?ei=IVX....0.xKxSjNXZWBY but I am confused about which 0402 would be the best to use for my ATF-55143?

If you intend to solder them by hand, 0402 may be a bit small.0603 will also be fine for 2.4GHz.

does 0402 and 0603 package refer to imperial or metric? if you search in google "0402 component size," it will direct you to a chart with imperial and metric columns from Wikipedia. I don't understand the difference and its confusing, because all of the numbers look alike and its just happens to be a coincidence?

0402 refers to the approximate size of the component 0.040 x 0.060". Same for 0603.

It could be potentially be either:

Metric 0402/Imperial 01005 is 0.4 mm × 0.2 mm or 0.016 in × 0.008 in
Metric 0603/Imperial 0201 is 0.6 mm × 0.3 mm or 0.02 in × 0.01 in
Metric 1005/Imperial 0402 is 1.0 mm × 0.5 mm or 0.04 in × 0.02 in
Metric 1608/Imperial 0603 is 1.6 mm × 0.8 mm or 0.06 in × 0.03 in

https://en.wikipedia.org/wiki/Surface-mount_technology