So, the story with Filco in the US: The main importer is
The Keyboard Company, a UK company. They use Amazon for fulfillment and send batches over periodically. Which keyboards are available or not available changes quite a bit. Lately browns have been in short supply... in the past reds were hard to find. Either way, I see you found the subform of The Keyboard Company... good. There aren't really many other options for a Filco other than in our classifieds. (A used Filco is as good as a new! Literally (almost..) nothing that can't be fixed.)
You may also look at the Cooler Master QuickFire Rapid boards. They are made in the same factory and tear-downs have shown the quality is nearly the same. I personally don't like the keycap font, but you can change keycaps... that's half the fun of a Cherry MX board!
As far as switch types, is there any particular reason you want brown?