Wiggle Hunt allows users to search modular shops from around the world for the gear they want. Search by name, filter by store, region, condition, and stock availability (helpful if you're looking for pre-order).
Right now, shops include the US, UK, Sweden, and Germany. More will be added over the next week.
I hope you find the site useful. If you do, please subscribe to keep it afloat. And please do not hesitate to reach out with any thoughts or suggestions.