Many G-fans are interested in collecting the vast amount of Godzilla and other kaiju related memorabilia that is currently available, from model kits and figures to posters and trading cards, all of which can be considerably valuable in the years to come. Companies such as Bandai and Marmit produce an astounding number of paraphernalia on Godzilla, Gamera, Ultraman, and all the other Toho, Daiei, Tsuberaya and even American kaiju (and sentai) that have appeared over the past few decades.
Several companies exist which sell this merchandise (as any Internet search engine will verify). For many years, however, the leader of these was most likely Club Daikaiju, owned by G-fan extraordinaire Jim Cirronella, who was also a regular contributor to the now on (indefinate) hiatus KAIJU-FAN magazine. Since then, it seems that Jim has closed up shop, but the good news is that he is now helping to set up The Godzilla Shop, as part of The Outer Limits sci-fi store.
So, these days, my best recommendation for finding cool Godzilla (and other kaiju) merchandise of every sort would be to check out The Godzilla Shop, and a direct link to that site is provided below.
Also be sure to check out the ad's to various Godzilla merchandise that can be seen floating at the top of the home page.