I don't think there's any limit on the number of products that can be bundled into a package product, but bear in mind you'd be expecting your buyers to hit 225 separate download links, so it may simply be more practical for you and your buyers alike to offer that package as a single .zip file download rather than using our "Package files..." setting, or even just mail out a physical disc with all that data.
A package deal cannot contain other package deals, but you could just select the same individual products for more than one package. E.g. if Package A issues files for products 1-3, and you want to create another Package B that includes Package A plus the files for products 4-6, you'd just set up Package B to issue files for products 1-6.
