Batch number reset

My company has used over 98,260,000 batch numbers. The remaining 1,700,000 batches will be exhausted within 3 - 4 months. When the batch number resets to 1 we have several questions.

1. With the reset will performance decline since the system will assign a next number to the batch and then validate if the batch exists. When it finds batches already exist and needs to try dozens of times before an unused batch is found will this cause issues?
2. We have been archiving data since 2008 and program R007031 has deleted many of our batch headers because the detailed data is no longer in our production environment. The concern is if the system assigns a duplicate batch number it will not be able to be archived in 2 years because it will be a duplicate. We Feel the best alternative is to restore the headers from our archive and prevent future deletion. Has anyone tried something like this.