i am thinking of getting a koi pond built, I am useless at diy so I want to get some one in to do the build, the pond will be 9ft by 8ft and 5 ft deep 30 inches below ground and 30 inches above just need it to be block work only as I am going to clad it with decking (well my brother in law is

as I am new to this I would like to pick your brains!!
anyone have a rough idea how much it is going to cost?
is using a liner ok for this deep?
do i need a bottom drain?
and finally does any one know of a good pond construction company in kent?
Thanks