whats the diffrence between all of them im looking to buy a new amp in the near future and am looking at all options.
Most of them, if not all, are no longer in production. I think MESA are currently designing and/or waiting to release a Mark 5. You might still be able to get the Mark 4 or Mark 1 reissue used though. What the differences are I don't know though.
R.I.P. My Signature. Lost to us in the great Signature Massacre of 2014.

Quote by Master Foo
“A man who mistakes secrets for knowledge is like a man who, seeking light, hugs a candle so closely that he smothers it and burns his hand.”