I suggest 6003-2RS bearings (IE sealed), normal or C3 depending on what is readily available. Use SKF or another respectable bearing company, not cheapo ones from China (except that some SKF bearings are made in China, but still seem to be good). Here in the UK we would pay ?4 or 5 each for them.
A quick look around Ebay.com finds item 133835772483 for $10 each. Most of the USA stocked items seem to be SKF, so that seems like a good choice. Prices generally seem to be around $10 each. Ignore anything from outside the USA. In this case it's best to have a more local supplier, and that still gives plenty of choice.?If you don't use Ebay there should still be a supplier near you.?The cheaper anonymous bearings from China and elsewhere are not to be trusted for a critical application, and to my way of thinking that's what this is. You want the bearings to last forever, ideally, so get good ones!
