any auto flash can work, as long as they support slave flash, or you can get a slave trigger. It boils down to how powerful u want the flash to be, ability to tilt/swivel, which will then decide which flash you should get.
The Achiever 260T sounds like a cheap option, about $45 or so.
What can the Achiever 260T do? I am just looking for a flash which allows me to use my A40 with my len adaptor. If I use the internal flash with my len adaptor. It blocks the flash and the pciture comes out part of it black.
ok lar seriously, it's an external flash lor! I think it has slave flash function (if it doesn't, get a slave trigger), so it will fire upon firing of your camera flash. When you mount it on a flash bracket, it will usually be beside your cam and higher, and the flash coverage should clear the lens adaptor.
Actually, if you just want to solve the lens adaptor blockage problem, just zoom in more lor, or remove the lens adaptor lor. A lot of people have the same problem.
Oh yah I forgot about this point, very important. If the A40 has pre-fash, your slave flash will fire off on the first flash, instead of the 2nd flash which is the one when the shutter opens. Unless you get those rare ones which ignore pre-flashes.