Hi, we loved the Lighthouse back in September 07, and we tried The Lemon Tree, both in quiet locations and were lovely. The Chef was good, especially the mixed fajita's, gorgeous!.
The Mandalin was very nice too, opposite the Indian restaurant, Taj Mahal, that's also very nice. Maybe not as quiet as you were thinking of , but if you like to eat early, (8ish,) then they're fine. No dancing on bars in these restaurants, but busy bars around them from 9ish. Suits me, because go straight from them to jig around in Linekers!