We have a lot of variants and sku's and I haven't found an automated migration extension that will work. Anyone know any companies that do manual migrations?
Have you checked out these people:
(I know nothing about them...this is what came up in a Google search.)
I have done a lot of migrations the past few years, feel free to shoot me an email.
Please also check (remove extra spaces in url)
https://www.shopping -cart-migration.com/shopping -cart-migration-options/2759-bigcommerce-to-cscart-migration