Why not go 15x7 / 17x8? That opens up a world of options. A 205/50-15 front 225/45-17 rear setup puts you in the tire market sweet spot.
And I wouldn't go R1Rs. They're really old, they don't have bleeding edge performance, but they're still not the most comfortable tire. Plus, they still heat cycle out, and for some reason they're still expensive. R1Rs were good 10 years ago, but the technology has moved on. Conti ECS is probably fine for street, but if you're going 15s, probably best to go with something like a Dunlop Z3.
2011 Lotus Elise SC Final Edition 15 of 15 - Ardent Red