hi ive seen a d7 ecu with original scoobyeuc daughter board are these good upgrades from z4 ?

 

6K is the best upgrade without need for a daughterboard but some people,including me, had a few issues with running them in a WRX (mine was causing a map sensor fault).
If you want a daughterboard I would save up your monies for an ESL daughterboard (http://www.enduringsolutions.com/)

 

do you mean 7d? if so thats a downgrade.