For $2k you can get 4 lightweight Apex Arc-8s 18x10, plus 4 Nitto NT-01s 275/35/18 square, for the same price as just the skinny Dunlops.
With the ESS SC you might consider the 10" up front, but 10.5" or even 11" on rear for 295, maybe 305s. However, the 10" square will be the most economical setup for you in the long run considering rotation ability.
2008 M3 Coupe / DCT
// StopTech BBK 380/355 / Pagid RS29 / Motul / Apex Arc-8 / BFG R1 / Ground Control / MS filter / Performance spoiler / BPM tune // Road Atlanta 1:39.70 / VIR Full 2:10.87 / Barber 1:42.20