Ragnarok Online Test Server
There are lots of stat calculators and skill simulators out there in the big big internet. But nothing beats playing your planned characters in real time. I found this test server powered by www.ratemyserver.net. The server gives players GM commands, summon monsters, change levels, etc2x. Everything you need for testing your characters and testing strategies with friends.
http://play.ratemyserver.net/ragnarok/index.php
Test it out. Screenies when I get home. 