We need this solution to work with bare-bones systems too, so Package Mapping will probably not work very well. Package mapping seems to require some manual work in the console and we don't give console access to our Techs. They just boot to WinPE and select the provisioning task.
Using queries to filter the package to specific models will work, but I see it being a nightmare to manage. We have many different types of hardware. Each time we get a new device in, we'd have to update the queries of the packages that support it. And what happens when we need to push the package without the filter? We'd have to create a new package without the query.
I think at this point, we're going to move forward with creating two provisioning tasks (x86 & x64) for each of our models. This task will include other templates, one of which is a task that installs these model-specific packages. There'll be a lot of templates to manage, but at least it's all in one location.
I guess part of the question was about how everyone else does provisioning it in their environment. Maybe we're over-thinking it in ours.