It depends. In order to use the petpet lab ray, you need to have the regular, pet lab ray as well. If you've already got that, or if you were planning to get a lab ray anyway, then yes, absolutely, buy the petpet lab map pieces and an Abominable Snowball and hope for the best.
Other options include buying a plain Kimbi and a Darigan PPPB from the Trading Post or Auctions, then painting the Kimbi with the brush. Or, you may be able to just look up "Darigan Kimbi" on the Trading Post or Auctions. If you do find one already painted, that may be your best option. Since painted petpets are notoriously hard to sell, you'll hopefully be able to negotiate a good price.
Good luck!
EDIT: D'oh, Huggles beat me to it. Sorry. Would someone kindly delete this post?