Thanks, I figured it out when I read the other page. I always ask what tuning people mean because although you and I say C tuning others say G tuning for the same pitch, because they read G as the first note. Always good to confirm. I linked your tuning page on my own, because it has good information on it.
Anyway, I have a set of baritone strings, but want to change the wound fourth for a re-entrant high D. I assume that would just be a standard first/E string dropped a tone. Should not be too floppy - I dropped tones on guitars for open tunings without any problem. I expect to order your set anyway, but it won't arrive this weekend when I plan to restring the uke.
On using guitar strings: you shouldn't need a very heavy set. The shorter length of the scale should mean less tension on the strings, so it strikes me a lighter set should work quite well. I think what I have on the Pono now is a set of D'Addario guitar strings, and my local music store owner says that's what he uses for baritone ukes. Besides, what I think of as light and heavy are based on steel strings, which are much thinner than nylon.