Some of the Specna arms/Cyma AKs are lighter than their LCT/E&L counterparts.In particular, the newer polymer furniture style. If you want an older model style some, of the TM AK47 clones are lighter. Think the G&G AK47s were light to the point of flimsy, so wouldn't necessarily go down that route.
A Cyma/Dboys AKS74U might do the trick? The latter is available with polymer body.