Black tie dinner, we need to buy a tuxedo/dinner suit, off the shelf due to timing. Shawl collar, single button front vs standard notch, two button front, both with covered buttons and satin lapels, and two vents vs single? I have no idea what's current or dated, though I know I liked the look of the shawl collar pure wool one we saw in John Lewis. Budget about £250 for jacket and trousers. Help!