The 2017 PIKO G scale catalogue is available as a free download on their website.
Link: PIKO Catalogue 2017 (PDF – 75 MB)
PIKO America also published a different catalogue for the American market.
Link: PIKO G Catalogue 2017 America (PDF – 29,9 MB)
Surpringly, the catalogue from PIKO Germany is not complete. Several of the 2017 new items are not included, and a lot of American items are missing (although they are for sale in Europe). So if you want a complete overview of the PIKO range, I suggest to view the American catalogue, or to browse PIKO’s webshop.