As I'm doing this more or less every weekend to make something I might can help here.
*Electric jigsaw and glue felt on the pad/foot to prevent gouging. Good ones around $60.
*Air reciprocating saw but doesn't do corners well. Around $25 budget tool which works well.
*Air shears but really only for straight cuts mainly. Around $25 budget, sames as above.
*Air or hand Nibbler, great for small detail work. I use a hand nibbler.
*Deburring tool, hand held, great for cleaning up edges from drilling and cutting.
*Clecos - used to hold the panel in place for fitment, $20 for a set.
For $150 you should be able to have capacity to do anything you need.
Start with heavy construction paper and make a template that fits perfectly. Then move on to ally panel. Measure a lot, cut once. Make sure you plan your folds ahead of time because you'll find sometimes if you make fold A first you can't make folds B,C, and D.