Porting, Reeds, Noss Machine Head, Ricky stator timing advance.
Get the carbs later. That way you know what size to get baised on your riding type and porting style.
When you do get carbs I would go with keihin PWK 33mm Carbs at the smallest. That is if you get a good port job other wise I would just stick to stock carbs. That is also what jeff at fast recomended to me. He said he wouldnt really waist time with 28's unless your going to just have pipes with no porting.
Some times porting affects the compression.
I would do the port job before you get a noss head. That way you can break it in and do a compression check to get a base line. Then you can get a better estimate of what your compression is going to be with a given dome size. You would be able to get closer to the limit of, pump fuel if you wanted to run only premium pump fuel. Swaping a head out later on isnt that big of a deal.
josh