There is no turbo kit for the festiva. Extractors, dump pipes and all that will have to be custom made. You would be better off buying a new turbo somthing like a GT25 or a VF11/VF12 that are used in most B6T cars (capri tx3 etc)
Over at forfestiva i was recently asking about NOS, you will need a wet kit and 50HP shot would be about the maxium that could be handeled. Local performance shops should be able to do a nos kit for around $1200
http://www.fordfestiva.com/forum/viewtopic.php?t=11773