The VG33 Valves are significantly larger so would use those heads if available Just put the VG30 cams in them as the VG30 is a slightly higher lift/duration. Doing so will give you some increased torque on the low end. Also make a note of the cam gears as yours will have the square toothed gears/belt and the VG33 will have round tooth ones. Use the round tooth ones from the VG33.
The brackets probably wouldn't be a big deal but the water pump housing will also need to be cut down on the right side to fit to the VG33 oil pump housing. It doesn't look to be a problem if you have some experience doing that sort of thing but if it was me id take an old pump and test cut/fit first before i went and cut on a new one.
The harmonic balancer adapter is not something the average person can just make up since the VG33 crank has a larger snout than the VG30 in that has to be a tight tolerance or you'll create some major problems in a short time That also means you have to have the VG33 oil pump and lower timing gear cover available to reuse. Would definitely recommend you getting in touch w MR 510 about that. PM me an Email and I will send you the Info as I don't know how to add a link here to his member profile. if someone reads this that does, please feel free to do so.