The simple answer is - whichever package you're most comfortable using.  I don't have PSP9 so I can't comment on it, but if you're using some sort of tool to draw that shape directly then you're making life difficult for yourself.  Much has been written about layers, they're nice but not always essential.  To create that shape you first need to mask it off from the rest of the fuselage and fin.  You should be able to move the edges of the mask around, or at least create one mask and then add/remove areas of it.  Once you have the wiggly stripe masked off from the rest of the plane, switch to an airbrush tool.  Start at the nose with yellow, then blend to a dark red behind it, then orange, then blue.  You can go back and overpaint any bits you don't like, knowing the rest of the fuselage is safely masked off.  When you're happy with the stripe (and only then), remove the mask.

Looking at that photo, the nose gear doors are yellow so there's probably a stripe underneath as well.  Same process, just do one stripe at a time.

Unfortunately, when you're starting to repaint planes, you WILL need to sit down for one whole day - or more - to learn how it's done.  Once you've achieved that it gets much faster, but the only way to gain that experience in the first place is to sit down and do it.

Gryshnak

just to add another option (and so you know, I use PSP as well) if you can find a decent side view, then  just cut the markings out of the photo / image and if they are good enough, just use that! or if not, use the photo as a basis for a re-created version of it, made using rhe vector line tools in PSP.