eBay would be the obvious answer, but the prices can be errattic. It's probably where you will find the best deal online,  although I know it can be a hassle to go the ebay route sometimes. There are a couple sets up on ebay right now that seem to have a reasonable buy it now price. Not sure where you're located, but you might want to check any local swap meets for used stuff. A number of the local Harley shops around here carry them, but they've always been too rich for my blood.  

http://cyclexchange.net used to have some 1" z bars, but the only type they have up there now are 7/8s. They might have some that are not on their website though, you could give em a call. I've heard nothing but good about them.

JP cycles carries the Paughco W- and Z-style Handlebars. They are not cheap but they are great quality. It is what I have on my bike. They have different rises and widths.

Just ordered a set off of ebay. 6" rise $30.00 Lets see what they will look like on the bike.

Hammy, I will post a pic as soon as I get 'em