IF you dont want to touch application code, you can take a look on BMC software, CA (Computer Associates), IBM and SUN.
Take a look on features on each of these and see what you really need.
I suggest you start on BMC site (www.bmc.com). Im not sure but i think the BMC product name is "proxima" or something like that. You can find a lot of papers there to see what they think is good...