Does anyone know where I can download CF8 developer edition

If you are migrating backwards, depending upon what you had, that could be a HUGE step backwards.  If the server only supports up to CF8 (hard to believe), then you might want to reconsider your choices and go with a server that can support AT LEAST CF10.

Meanwhile, to answer your question, I believe that you can get the CF8 installer (please reconsider) from this link, which is a CF repo.

V/r,

^_^