Digging job + concreting

I've got a 4.5m x 3.5m site in the back that will need to be dug. I'm estimating 8 to 12 tons of dirt to come out. I've killed the stumps there, but I expect roots to slow down things somewhat. Regarding the access, there's only one digger that will fit through the passage, and that's a yanmar sv05, in case you can get your hands on one. I'm prepared to pay a sum between 2500 to 3500 pounds. If you can make also a surface for a garden room - 100mm MOT type 1, 100mm concrete - we can discuss the price for that one too.