Only thing I can input is that you should make sure the spray cap for the paint sprays evenly. Some I've found are really fucked up and spray in an uneven pattern. no not like a hard centre soft edges kinda spray (I consider that "even"), I mean like a really fucked up spray pattern (culprit was dried paint and dirt or something stuck in the spray cap).
I'm not sure what "rattle cans" are so I can't really say anything about that (if they're the paint with metal "marbles" inside to mix the paint before spraying they should be fine at least that's what comes to mind when you say "rattle cans").
Krylon (from Canadian Tire
(or Walmart)) works wonders from what I hear from other kraken owners on the forum. Basically any mediocre paint should be fine. Remember lots of thin coats is better than one heavy one and also helps to prevent drips. You should have all the knowledge to do all this since it seems like you know a bit about painting (with the roughing up with sandpaper thing).