Ceramic antenna for wifi applications
The only figure that really matters is efficiency. Choose the most efficient antenna that will fit in your enclosure.

Gain is derived from efficiency, and the pattern will be shaped mostly by your PCB and housing, not by the antenna itself.

VSWR needs to be low enough, but it should be possible to tune all antennas down to 2:1 or so, which will be fine.

One last thing: you will almost certainly need to tune the antenna after installation - the exact shape of the PCB ground, and the housing plastic will pull the antenna off frequency. Some small capacitors on the PCB will fix this, so build in some pads for a couple of caps in series and parallel. When you have a final board and plastics, measure the antenna VSWR and adjust it appropriately. Most datasheets should describe this procedure.