Shimming is your call.. I did it for awhile without any issues, only to about 9psi though. I would go with a Toyota HG and spray it with copper spray.( I have heard of others using brake quiet as well) The stock head bolts won't be able to handle as much torque as the ARP's. You can install the head with studs without too much trouble. It would be a little easier if you could remove the EGR junk.. Check you local emission laws! Just make sure the threads in the block are clean before installing studs. I installed 2 studs in the front of the block. 1 on each side of the block to help keep the head straight. I have been running 12psi since July.
Just my $.02...