I think it's best to get Sola from ebay. You might have extend budget by another 1.5 - 2k. Sola should get official JB. Even if it doesn't, there will be good JB roms as it uses same soc as Xperia P
U will hit you badly storage.
A21 won't have quality to survive for 3 years.
- - - Updated - - -...