KCU-COM. Here is why:
-One of the founding DO schools
-Many tracks available
-Established DO program with GME programs (including derm)
-Kansas City is a major city and has more opportunities for you in terms of food (great food scene), nightlife (those post-exam night outs in the city), sports (football, baseball) and museums. In addition, the city itself will give you more access to potential research (KCU itself does not have too much research but other institutions in the city do)
In terms of COA, I see that KCU-COM is $76,334 vs ARCOM's $76,108. The differences are negligible and your money will go farther in the long term if you choose the more established program.
Finally, the matches for KCU-COM are quite good and are across the nation.