Here is a photo of the rivet gun and bucking bar I am using.It is a 4x (a 3x would do) from aircraft tool supply.
http://www.aircraft-tool.com/shop/de...t.asp?PageNo=2
It has a very nice trigger which gives a lot of control.I would not use an air hammer to buck rivets.I looked at my two air hammers and their triggers are more or less on/off no control.I installed a valve on air inlet to throttle down pressure a little.You will also need a rivet snap for the 5/32 rivets.
http://www.aircraft-tool.com/shop/de...t.asp?PageNo=3
And a bucking bar
http://www.aircraft-tool.com/shop/de...t.asp?PageNo=1