I'm normally a huge proponent of dry-hopping with Nelson, especially if you want to tweak a style that isn't normally dry-hopped. But I'm picturing a big clash in a BGS. Nelson is potent, and I'd be afraid that the grapefruit and white wine character wouldn't be such a good fit. But I've never tried it, so if you use a light hand it may turn out fantastic for all I know.
I love Caliente in dark Belgians. The plum note pairs amazingly with Special B, D-180, WY1762, etc. For a lighter Belgian I'd be tempted to use Meridian, which is more on the peach/apricot side of stone fruit with less citrus than Caliente. Safe choices would be noble hops like Hallertau, Tettnang, Styrian Goldings. Sterling is another noble-type hop that has a bit more fruit as well.
Whatever you decide to go with, please report back with your results!