Sun x GCC hybrids often have high chick mortality rates, are born with foot deformities (among who knows what else), may die early of cancer (i.e. before a year old) and fertility is unknown.
Suns have also hybridized with black capped conures.
Green cheeks have also hybridized with nandays, dusky's and supposedly patagonian conures.
There's also maroon bellied x dusky hybrids.
None of them are particularly interesting hybrids to look at other than the fact that they are Pyrrharu x large conure hybrids.
Of all the hybrids out there, I do not feel it's right to hybridize Pyrrhura and large conures together due to the potential health problems. With most hybrids, the worst that you see is infertility. Well, the majority of hybrids created are rather healthy birds that can reproduce!