I know for a fact that both McMaster-Carr and MSC Both carry 1/2 flanged bearings.
McMaster: 6384K361, $6.21
MSC: 01377266 $3.53 (Cheap-o)
However, for small rotations, bronze bushings aren't a bad move either.
McMaster-Carr # for a 1/2 ID, 3/8 THK Flanged Bronze Bushing.
6338K417
Hope this helps! Good luck!
Matt