I'm confused what you want. Do you want to reinstall gtalk to restore market? Or you want to install a custom rom?
The latest google apps including gtalk can be downloaded from [DEV][ROM] CyanogenMod 7 (Android 2.3.4) - xda-developers
ClockWorkMod for defy can be downloaded from [RECOVERY] DEFY ClockworkMod Recovery - 22.214.171.124 - xda-developers