You should find that any highly-rated bundle builder app ticks all of those boxes. I recommend installing a few and playing around to see which one feels right for you. I actually developed the Sumi bundle builder app, if you’re looking for options! ...

In case anyone else is looking to achieve this, it can be done with bundle builder apps like Sumi. 

Hey Trey! It's tough to diagnose the problem without a link to your store. I suggest emailing the Section Store team at help@section.store — I'm sure they'd be happy to help! You could also try some other bundle builder apps:Sumi - Simple Bundle Buil...

A “bundle builder” app like Sumi would let customers select 5 items from your collection of products for $25:https://apps.shopify.com/sumi To send the digital files (PDFs/PNGs) after checkout, you could use Shopify’s Digital Downloads app, which auto...