I can't speak to VBox setups as I don't use it. Hopefully I can help with the NVIDIA driver setup.
When installing the NVIDIA driver through the .run file, you'll need a few things first. The big primary one is dkms, which is available in the EPEL repository. I would also recommend installing the libglvnd-* packages, otherwise the NVIDIA installer will utilize its own rather than pulling from a repo, which will later get overwritten when you install libglvnd through some other dependency.
RHEL (and CentOS by extension) follow a kernel ABI for its modules, as designated by the kernel-4.18.0-<ABI-version> naming. This means that if you compile a module against 4.18.0-80, then it will work with all 80.xyz kernels that get released. It will
not, however, work with the -147 kernel found in RHEL 8.1 thus requiring a rebuild which is where dkms will come in.
An alternative option to this is using the ELRepo, negativo17, or RPM Fusion (non-free) repositories (personally I use ELRepo, have been since EL7). The teams on these repos build kmods (akmod is available in RPM Fusion) that have a kernel module prebuilt for a particular kernel ABI using the tools native to that release so that you don't have to worry about dkms or other packaging. Compatible packages are denoted by the extension 8_0 and 8_1 for the release they are ABI compatible with. These packages will also go through the necessary steps of disabling and blacklisting the nouveau driver for you as well, so you don't have to worry about that part.
ELRepo currently has the NVIDIA driver (440.36) available for both 8.0 and 8.1 available in the elrepo-testing repository. These are
not compatible with the CentOS Stream kernel, only the released kernel ABIs they are built against.
http://elrepo.reloumirrors.net/testing/el8/x86_64/RPMS/
You can also just take the spec file from the SRPMs and adjust it if you need/want a different driver version for your desired kernel version that isn't offered by the repos.
The CentOS Stream repository currently has 4.18.0-147.3.1 (which is the current latest RHEL 8.1 kernel at the time of writing) which will work with repository NVIDIA packages that support 8.1. The
latest stream kernel is 4.18.0-151 which will not. I would follow Trevor's advice and use the CR repo, as that will provide you the base 8.1 system and not anything newer for compatibility reasons.
http://mirror.centos.org/centos/8-strea ... /Packages/
Everything above is to the best of my understanding and experience, so if any of it is wrong or misinterpreted I expect Trevor or someone more experienced will correct me
If you have already done a .run installation and registered the driver with dkms, I recommend deregistering it as stated in the NVIDIA driver documentation:
https://download.nvidia.com/XFree86/Lin ... gTheNda02d
Cheers,
Mike