Hi,
You are mentioning that you don’t want to automatically charge your customers. For this, I recommend you to try the Seal Subscriptions app (https://apps.shopify.com/seal-subscriptions), which also has the so called “recurring invoices” mode. In this mode, the app won’t automatically charge your customers. It will create a draft order, which you can then mark as paid. You can also turn off the option to send the draft order to the customer, so that you can manage this on your own.
And it is also integrated with Bundler - Product Bundles app (https://apps.shopify.com/bundler-product-bundles), an incredibly popular bundling solution.