"going to try the rustoleum technique ive seen online,"
I've been looking at this approach too. I figure that the Wattyl Killrust and Dulux Metalshield are somewhat equivalent products. Both the above are epoxy enamel paints. When I searched Rustoleum I found that Bunnings carry some Rustoleum paints and it seems to be a brand name so it actually incorporates a number of paint types some of which are acrylic and some which may be enamel and perhaps epoxy enamel. So make sure you are using the type of paint you really want and that will give the results you are after.
Searching Rustoleum I also found this instructional which may be what you found:
https://www.instructables.com/id/Paint-Your-Car-With-Rustoleum/. I figure Wattyl and Dulux products I named are roughly equivalent paints. Dulux offers a rust suppressing etch primer but does not offer or recommend a rust converter as part of its system. Wattyl says their paint does not need priming. I think they do suggest a rust converter for rust that cannot be removed. The Wattyl product comes in a fixed range of premixed colours. I figure they could be mixed to achieve other colours if desired. The Dulux paint however can be mixed to match most of the colours on a Dulux colour chart. If that provides accurate colours then that means a huge range of colours become available to select from.
It may also be possible to add a hardening agent to speed up drying and improve durability. I haven't investigated this but it is mentioned in the comments following the instructable that I linked above. I don't know if this would make the resulting paint more hazardous to use.
In my mind I fancy a 2 colour job with a lighter blue above (closely matching the original colour) and a darker colour below the chine line that runs front to back just below the top of the guard and just below the bottom of the window glass.
All this is a long way from getting the door handle off your VN but please consider keeping us updated on your project if you do take it on.