When I logged in last night I did not see a separate spot in pilot lab for the 5N(C). Considering that the MC price for the 5N(C) is only maybe 20-25% more than the other dragons, I actually think it's a better value than just buying a 5N with MC. With that said, the 5N is probably the least desirable Dragon model (it only makes use of its specific hardpoints in a 3xAC2 build, which is a big compromise), and I prefer buying chassis with cbills unless its a Hero. But if I were to buy a non-hero chassis with MC, it would be a champion.
They might have changed it with the latest patch, there was a seperate spot when it was on trial. Haven't been able to play the new patch yet.