#1- only use oem head gasket
#2- if you have access to a flat piece of granite tape sand paper to and sand the tops of cylinders and bottom of head, I use a three paper progression 100,220,400 finish. Sand in a figure 8 pattern and count revolution so you can evenly do both cylinders if you have no measuring equipment.
#3 - during assembly slide cylinders on without tightening base nuts, then tighten all head bolts good n tight then do cylinder base nuts. Then torque head
I use three bond 1211 instead of copper spray. I've used three bond in place of a gasket and it's held up so I think it will work just fine for your application. I'm also a firm believer in testing everything before tear down and after assembly. Make sure your allowing 24hrs cure time for any glues or sprays your using, if it's cold out it takes longer. If it's not fully set up it will get pulled/pushed out of crevices and seep leaving you with wasted labor