If you have a table saw and router, you can actually make your own bar rail to whatever specifications you want! This is a very advanced table-saw operation that should be done by only people who are very comfortable using a table saw. Here is a link to a website that details how to make the cove cut in the wood.
http://www.binkyswoodworking.com/CoveMouldingTip.htm
For a bar rail, first use the router to round the edges, and then cut the cove cut in the wood. I’m cheap and dont like to pay for stuff I can make myself. By the way, if you choose to do this operation, I’d suggest trying it on a few short pieces of pine before using some expensive oak boards or something.
Or, you could always buy it . . . . .