For Sunspot, I'd say evolve sooner rather than later. You can always TM flamethrower. If memory serves, helping hand isn't all that useful, and agility, while helpful, might not be best if it means waiting for level 43. Honestly don't know the moveset Growlithe/Arcanine have in gen III, I ended up going straight from Gold to Heart Gold, they get any decent physical fire attacks this gen?

For backups, I'd say train up Karp Karp, Bumbles, Endo, and Zephyr.

Honestly forget who Fluffles is, so cannot comment on that one.

I have no preference for Dee-darr, though seeing its fully evolved form obsessed with nothing but skittles could be cute. Forget which evolution that is though...