if you want professional looking results--try the sheet metal brake/shear/press from Harbor Freight--go to
www.harborfreight.com and search keyword 'shear'. A good one is about $400--a really good one (40") is $500. They are awesome, and cut fabrication time in half. If you search CC for aluminum panels, I think Brent hotlinked directly to the smaller one above that he used on his car to very good effect. Remember---there is no such thing as a bad tool investment (as long as your wife doesn't find out!).
The three common ones @ Harbor Freight are P/N'S:
5907-8VGA ... 30" capacity.... $400
43353-0VGA ...40"................. $500
41162-4GVA.....52"................. $970
I bought the 40", and have been very pleased. It made everything I needed and then some, and now is a nifty looking ornament on a sidebench in my shop. Watch for sales--mine was only $349 here in Dallas.