Add cruise control to a 2003 ST 5 speed.

[KingS]

Not sure if this has ever been asked on here and search function doesn't work on my phone so question is: What all is needed to add cruise control to a 2003 ST model with 5 speed. I know the 04.5 and newer most the time you just have to buy the switches but the 03-04 st are different and not sure besides switch on steering wheel what all is needed.

Thanks for any help.