Cheap cloth diaper cover recommendations

We decided to use cloth diapers. After doing a TON of research I think we are planning on using flats/prefolds with diaper covers. I'm trying to save as much money by going the CD route and really don't want to spend a ton on a cover. Any mommas have covers that you absolutely love? Or ones that you wish you didn't buy? Also did you use them from birth, if not what NB diapers did you use? And how many covers do you need? I've read 6 will be enough with 18-20 flats/prefolds? Thanks so much!!