USPSA, IDPA & other clubs use a lot of plate racks.
Some of MGM's stuff is excellent. Other stuff, not so good. (I do not recommend the Texas Star by them.) Our club hasn't ever owned a MGM plate rack, but I'm sure I've shot one somewhere.
Here are a few other places to start looking;
www.ArntzenTargets.com
www.nevcotargets.com
These two places advertise in the USPSA magazine. You can also contact the USPSA.org to see if they have any good recommendations. (Support the folks who donate to the sport so to speak.)