Lori Loughlin and Mossimo Giannulli are gunning to head south of the border once more -- only this time, its for a wedding ...

Lori cites the $150k fine she had to fork over as part of her sentence and says she's done with her community service.

Mossimo, for his part, says he's paid his $250k fine and says he's making progress on the community service.