I don’t think Hori has any official retailers that has a physical store in the US. You won’t find them at Gamestop/EB games which sells the MadCatz TE stick.
That being said, you can still get Hori online in the US from the following website.
you can always try eBay but you probably wont find one at the $99.00 MSRP.
Yes, the white HRAP3 is the Amazon.jp edition so you won’t be able to get it in the US through official distributors. Again, there’s always a chance to find it on a US auction site.
hope this helps.