The D'Addario site shows they do a 55 75 90 110 set too. Also a 130 single.
So yeah start with a light 110 for C#. A 130 would be tight.
Umm... a tension balanced set would be... (applies method)...
Gb 40
Db 55
Ab 75
C# 110
That's the heavy set without the 90, plus a 40. Cool.
Now, to check my method of choosing gauges, here are the tensions for half rounds using the
D'Addario tension chart pdf.
Gb 40 32.4 lbf
Db 55 33.4 lbf
Ab 75 33.4 lbf
C# 110 31.6 lbf
Looks good to me, 33 pounds is a light tension without being overly loose.