think is what split-package means), wouldn't users need to have dependencies installed sufficient to build all of them?
Whatever is listed in the top-level depends and makedepends will be installed during package build. Package-specific depends can be listed (or appended to) within the each split package's _package() function (otherwise the top-level depends is used).
In that case, should I have separate PKGBUILD files?
No, a split package is appropriate. PKGBUILD files are intended for package maintainers, not for consumption by AUR helpers. ;)
OpenPGP_signature
Description: OpenPGP digital signature
