Right now I am running Wiseco pistons, V-force reeds, and T-5's. I am getting my cylinders mx ported and getting a Noss head. I am between 500-1000 ft above sea level. I want to run 93 octane so what domes would you suggest? I was thinking 21cc would be about the best??

 

With the mods you've listed, 21cc domes should be fine. Depending on how the porting is being done you may be able to go smaller.