I just finished this project last night. What I did was go with all new strings. I used 2 sets of Martin Bronze medium gage accoustic guitar strings.

I made hoop ends using the end that would normally go in the machine head of the guitar by making a loop with my fingers and clamping the ends with vice grips. I then twisted the hoop with a screw driver. I cut the eye ends off and put those in the machine heads. All the strings are double coursed except the low C

Caution:

If you try this be careful as the stings are sharp after you cut them. You can poke your self easily (ouch) and I would wear eye protection also. I used a file to take some of the share edge off

When making the hoops it is tricky to get the sharp end out of the way so you are not scratching yourself. So pay attention there too.

I also adjusted the tension of the head up a good bit as some of the bolts were only finger tight from the factory.

Results:

I like the tone of the ADGC courses quite a bit. The tension on the G strings are a little loose (insert free joke here) but still sound good. The F is decent but the low C seems too low for the cumbus, at least for the string gages I am using. I suspect that DGADGC would sound the best for this string setup but I have not even had a chance to get the strings stretched out yet. More test playing is needed before I know if I think it is worth the effort time wise.