Well I would assume that Calm and Bold compliment the ParaFlinch sets better because they don't necessarily rely on damage as much as pressure and staying power, but Timid and Modest make a lot more sense for a Nasty Plot set that is probably going to be extremely aggressive.
Took me 3 hours and finally got a chlorophyll bulb with decent HP IV, Modest though even I'm trying for Timid but alas giving up. With Thick Fat now I should Invest EV on HP and S.Attack?
Growth
Giga Drain (hopefully through Z tutor)
Sludge Bomb
Sleep Powder?