You might not even need a better amp.
If ya have full access I did a few tutorials on what the different effects are capable of doing for your sound. I did em straight line in to the computer using a GT-8 and it should give you a good idea of what you can get with a decent multi-effects unit.
Try checking out this lesson. It gives an example of playing straight through the computer, then adding reverb, delay, chorus and compression

http://guitartricks.com/lesson.php?input=10684&s_id=395