Thanks Lugia, you are really showing me very good points I never thought about...I will surely consider the 7U case option very carefully, you opened my eyes about it!
Thak also to you Garfield, you don't have to apologize. Every comment I recieve from people more expert than me is extremely valuabe. If I was sure about my choices I wouldn't have posted asking for advice. I actually am keeping my eyes open with much interest about Gronud Control and Black Sequencer! As I said, the sequencer is something I'm still trying to leran more about, so if you have any other advice about it I will surely be glad to hear them!
One more thing. Do you guys think it would worth it to look for a dual filter in order to filter more voices independently?