Thanks everyone! I'll definitely buy one then, only for watercolouring, the next time I order from Oozak.
Kamstutz, I googled versafine re-inkers and got these:
ONYX BLACK - Versafine Reinker Ink Bottle - $4.99 : Monkey House Hobby and Home
$4.99 but I've never heard of them. I tried to find shipping info, but it's not entered yet: Shipping and Returns : Monkey House Hobby and Home
VersaFine Reinkers - refill Black or Sepia VersaFine ink pads
$9 but I've heard of blockhead stamps before. They offer free shipping over $100.