Solaris 10 can handle something like 16384 devices even in a 32-bit environment.
Why does PowerPath provide duplicate device entries?
If you disable PowerPath and enable MPxIO, do the duplicate device entries go away?
I would try to find out from EMC how to resolve the duplicate entry problem.
Limits exist also on the FC card driver. Please check too on this side.
Check LUN id limitation for one initiator on the storage side.