With the spelling of a name you can do anything you want. If the "C" is important to you, feel free to spell it that way.
However, I would point out that having names that aren't commonly spelled, and/or are not apparent how they're pronounced can be a real burden on a kid (just look at my names, I've put up with it all my life.)
You should also be aware that every study I've read indicates that if the name is too far from the norm, children tend NOT to achieve as well as their peers with "standard" names.
You'd be amazed at how stupid people can be when it comes to names. The "G" Geoff is the same as the American "Jeff" (g is the brit spelling), I've had people call me all manner of weird stuff, the most common is "Godfrey" and I say "there's no 'd' in that name" and the idiots say "godrey" right back to you. The Germans don't use a hard "G" so there I was called "Scheff" for 6 years. Goff and Gee-OFF are also common. Normally if they get out a "guh" or a "buh" sound, I end up responding. I tell people to think of 'george' (my Dad's name) without the 'r'.
So, it's worth putting some serious thought into the name and how it's spelled. It seems that male children tolerate 'different' names less easily than do female children.