you can try www.thawte.com (raising prices in August)
you may also view www.geotrust.com web site (you can also search for their resellers that usually charge much less than list price on geotrust.com web site)
Just to note, Geotrust QUICK SSL is only supported by newer browsers (Netscape 4.7+, IE 5+). The eBusiness ID is supported as much as Verisign/Thawte's. Some hosting services have trouble installing this though, and its more expensive.