You can also check out
Small Parts . They have 1/2 inch bearings for around $6 or a pack of 10 for around $45. I do not see it listed with a flange on the small parts site, but I know if you ask for it you can get them flanged. The bearing that they sell is actually already in CAD on the
www.firstcadlibrary.com site under the bearings section. You will also notice that the part number on the firstcadlibrary site is the one for small parts.
Eric