In my opinion, the easiest way to get to a Stock DK28 Froyo Rom with Clockwork recovery built in( allowing you to flash custom Roms) is right here
[Stock Flash][Odin]Dk28 Extended 12/05/2010 inc. Root,GPS hack,Clockwork+Redir. - xda-developers
Heres the Download
Multiupload.com - upload your files to multiple file hosting sites!
Put your phone in Download mode( Volume Down, Camera, Power Button) Open Odin, select the modem pit and pda file, hit enter, and Enjoy!