Folks, after a thorough search, I found that Element 14 also stock the Rubber Duck Antennas Lewis uses:
900MHz 5 dBi Rubber Duck Antenna HG905RD-RSP
https://au.element14.com/l-com/hg903rd-rsp/antenna-rubber-duck-gsm-900mhz/dp/1900215
2.4GHz 5.5 dBi Rubber Duck Antenna HG2405RD-RSP
https://au.element14.com/l-com/hg2405rd-rsp/antenna-wlan-2-4-2-5ghz-50-ohm/dp/1862233
Looking at the datasheet for the 900Mhz antenna shows that it will work from 860 Mhz to 960 Mhz which easily covers all international Z-Wave frequencies.
EDIT: Here is the RP-SMA to uFL/IPX/IPEX RF Adapter Cable & SMD connector too:
https://au.element14.com/adafruit/852/accessory-type-rp-sma-to-ufl-ipx/dp/2816252?st=ipx
https://au.element14.com/hirose-hrs/u-fl-r-smt-01/rf-coaxial-u-fl-straight-jack/dp/3908021?st=ufl
