The SB in my MK2 Golf van is extremely poorly (Head Gasket

)
There are 2 options open to me at the minute......
To rebuild it, but want to build it strong and able to run lots of boost (was running 20psi through a K14 when it went pop!)
What is needed to stop it coming apart again?
I've been told to use a 1.9 head gasket and 1.9 Nozzles.....The question is, what 1.9 HG do I use and if the 1.9 nozzles give noticeable gains, which ones do i need??
OR......
I have an AAZ available to me to transplant into the van......
Is the AAZ as tuneable as the SB? Is there much wiring/loom work involved in an AAZ transplant?

?
Please help me!!!!
