The octave-lower strings from Guadalupe are pretty cool, but on a concert scale length I think you'll be bumping up against some laws of physics in terms of getting any kind of tone, and the string diameter / tension calculus for that short a scale length ...I would guess that for there to be enough tension for the strings to be playable, they would have to be very fat.
On the other hand, you could order a set of the octave low strings and try them out. Maybe you could just tune up from gcea a half step at a time until you got to satisfactory tension... or your bridge pops off...
Or you could mess around with classical guitar strings..two Ds for the 4th and the 1st (G&A) and A and E strings for the 2nd and 3rd (C&E). But I would expect some unhealthy structural issues with your uke with that much string tension.
Not that I'm any kind of expert, engineer, luthier, or physicist, but I've given this some thought too.