Storage size questions

Hi there, I ordered an ipod 5.5 30 gb model off of ebay. I plan on putting in micro sd storage and am wondering which of the storage solutions I have in mind would be the best for me.

For reference, I don't have a massive music collection, but I'm planning on putting mainly FLAC's of albums I have and some individual songs from artists as well as movies in the video department. I doubt I will hit the 20000 limit.

Anyways, my storage options I were considering were a single 512 GB card, 2x 256 GB cards, 2x 512 GB cards, or a 512 and 256.

I know a lot of things are subjective but I'd figure I'd have luck asking some people who know more than I, so thank you in advance.