Saison is a pretty wide open style so you'll get lots of different answers. Don't worry about it being too light - saisons are all over the map in terms of color (and flavor). Mine is light, too. But it needs to be highly attenuated, and Belle will get you there. Mashing @ 147-148F/ 90 mins will get it down to the 1.004-1.002 range or slightly lower, but Belle will leave a nice mouthfeel. As for the hops, it's personal preference. I wouldn't go too heavy with late hops given the lemon and basil additions. But if it sounds good, go for it.
Edit for piss poor spelling.