wht about we upgraded saab to a jet powered planeZDK-03 does not have an AESA radar. It has a rotating PESA. Erieye is superior to it as a radar but being a wedge design it does not have 360 degree coverage. Chinese KJ200 and 500 series use a circular AESA design which may be the optimal solution, since it is AESA with 360 degree coverage. ZDK-03 can be fitted with such a radar too, something I hope Pakistan considers in the future, since The platform itself is superior due to longer range.
Saab-2000 is fine as a platform for AWACS, the space or upgradation issues you mentioned are not actual issues.