bleary, nac and I use Rhino 3S2150 25c lipos in our Skywing MXSes and like them a lot. As to which lipos you might consider, look for something with a high C rating that's under 200g approx. Our 25c Rhinos are 185g and are 1-2 years old, though I'm sure there are higher c rated ones now of a similar weight for similar money.
BTW The photo below is a colour scheme that nac designed. Does it remind you of anything? feda passed this design and a few others that nac created onto Skywing and they modified it a bit to create the yellow Extra