We do have specific chassis for particular sabers, but we just don’t have a specific/custom chassis for each saber out there (although the offer is constantly increasing).
Browse the various Cx sections off the shop (ex: C1 – Solo’s Hold, C2 – KR-Sabers, …). If you don’t find your saber model there, it has not been produced yet. You can measure said saber and find the corresponding chassis module in the Mx or G2 – All-In-One sections.
Note in the case of Vader’s Vault hilts: they are only sold already installed (complete sabers) and not for DIY, so we have no VV specific Chassis. However, some may look into upgrading these saber with a better chassis. Same as before, first step would be to measure the hilt (ID and length) and check the Mx or C2 section to find the modules that could fit.
General rule: Chassis OD = Hilt ID -0.01″