Although my choice of which bike you should get next was to get the twin, I do think that given the means to do so, you will eventually want both.
And I think most of us would agree. You can't just substitute another bike for a C5. It can't be duplicated.
Get the twin next, but it won't be the same vibrating thumper that we all know and love. And the C5 will never be an Interceptor either...
At some point you will want another Classic, and you will still want the Interceptor too, more than likely...
And the Chrome Interceptor is a really nice choice...just needs a little more orange.