New to boutique buying -- need help with studios and resellers

[Splinterverse]

Hey. Longtime digital purchaser, now growing a physical media collection.

I'm mostly focused on 4Ks, but also open to blu-rays for titles that are unlikely to get a 4K release (like many Vinegar Syndrome releases).

Thankfully, 4Ks are region free, but for blu-rays I really want region A or region A-compatible. (I know about region-free players but haven't purchased one.)

I'd like your help to identify any boutique studios or resellers I've missed in my bookmarks. Here's what I have so far:

==STUDIOS==
101 Films
88 Films
Arrow Video
BFI
Cauldron
Celluloid
Criterion
Curzon
Discotek
Drafthouse Films
Eureka
Imprint Films
Indicator / Powerhouse
Kino Lorber
NOVA Media
Plain Archive
Radiance Films
Refuse Films
Scream Factor / Shout Factory
Second Run
Second Sight Films
Severin Films
Shameless Screen Entertainment
Terror Vision Records & Video
Via Vision Entertainment
Vinegar Syndrome

==RESELLERS==
Amazon
DiabolikDVD
eBay
Grindhouse Video
HamiltonBook
Orbit DVD
RareWaves (UK)
Unobstructed View

Thanks in advance for the help!