I don't have any recent experience with newer CF cards, but if you stick with name brand they'll probably be fine. Sandisk, Lexar.

Many of my own empegs have no-name or A-Data CF cards in them from more than 10 years ago.

So, look for a "CF" type card (not CFexpress, not CFast, not XQD), and stay at 128GB or less. Anything larger will be troublesome for the empeg with its limited RAM.