I would not use an interior latex paint (or any latex paint) in a marine environment. I just don't think the adhesion would be there, particularly on a non-wood surface. Remember, this is a moist, often cold, often oily environment.
I vote against the interior latex if only because the possibility that it doesn't work would mean a redo job that is worse that the one that faces you now. Sorry. Two votes "nay".
I have not used it but apparently BilgeKote is supposed to be pretty good at this application. I seem to remember hearing that it is not as susceptible to poor surface preparation as some other products. But I am not sure how different it is than Brightsides. I would err on the side of good preparation regardless.
Tim Lackey (www.lackeysailing.com), a boat restoration guru, swears by BilgeKote. His website is great and he does gorgeous, high quality restorations.
here is an excerpt from one of his restoration logs about BilgeKote: "It was time to paint out some of the other portions of the interior, including the hull ceilings in the v-berth and saloon, as well as the starboard side of the head inside the hanging locker and storage bins. For these areas, I chose white Bilgekote, since they will mostly end up being hidden inside lockers and otherwise closed in (the exception being the v-berth). Even in the v-berth, I thought the Bilgekote might be a better choice for the hull ceilings, since it is very durable and sticks tenaciously to anything. I thought it would hold up better than the treatment I chose for the more exposed areas of the boat--and has the added bonus of being easier and quicker to apply."