ridgeview,
Most pneumatic shears can't handle 16 gauge, and many people don't like the finish a nibbler gives. I have enclosed a link to a electric shear that is cheap, and will probably do the job on a hobby basis. This type of shear is cool because you can follow a curved line.
The crucial thing on the sandblaster isn't PSI, but CFM. If you have a small compressor, the syphon type blaster can do light work and not kill the compressor. A pressure pot style unit will make easier work of sandblasting, but will use gobs of air, and is best suited for a larger compressor.
Check the CFM rating of various types of sand blast units and compare it to your rig. A fairly good gauge is 1 HP (electric motor) equal about 3 CFM of pump output.
http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=92115 Stuart