Skunk2 has coil overs available now. They are listed for the Matrix but they will work for the Vibe as well.
http://www.skunk2.com/http://www.mmrusa.com has them for sale for $309.95 part # 517-08-2450 and on that site they are listed for the Vibe as well. Once at the do a search for Vibe or Matrix and you'll find them. quote:Whether your vehicle is set up for everyday street driving, weekend racing at the track, or strictly for show, the Skunk2 Racing adjustable coilover kit is your solution. Each kit comes complete with hard-anodized CNC-machined threaded aluminum sleeves, CNC-wound SAE 9254 racing springs, and mounting hardware that allows up to a 3" drop (sometimes more). Our dual-locking perch design has proven to be the most reliable method for securing the spring perches. The key to the coilover's performance and unsurpassed ride quality is the advanced spring design technology that allows the use of higher spring rates with minimal compromise to ride quality.