Best pre folds!?

I’m using pocket and inserts primarily I have a stash of 41- plan on purchasing 9 more. Anyways my mama was at a thrift store and saw two covers in immaculate condition. I had not really thought about covers before but since she picked them up I’d like to give them a try 🤷🏻‍♀️ I have two I’m unsure of the brand but they are Velcro, I plan on purchasing 3-5 snap covers from Alva baby... but I’m totally lost on where to buy my pre folds 😭

Any recommendations? I plan on using the covers and flats primarily on the weekends or on wash days!