What additions/mods would ya recommend for a SMC?

I plan on ordering a Weber 721001 Smokey Mountain Cooker.  Was wondering if anyone had any suggestions on additional supplies I would need to make it amazing.  One item I was looking at getting was possibly a cast iron grill for steaks.  Not sure if anyone uses the smoker for grilling but I was thinking about it.  Also curious about how many of you use the smoking guru controllers and if they make a big difference in performance for smoking using the SMC.  I am really excited about this purchase and definitely interested in all feed back.  Thanks....