FO in a C402..
Why the hell would you pay for that??
In my view you should find somebody with an aircraft type requiring (by CERTIFICATION!!) a copilot. Any company would not see SIC on a C402 as valid experince (I still doubt my SIC on a Kingair200 as "real" time..)
BUT... if the flights are p91 then make sure you fly as PIC OR even better spend your cash on REAL FO time on less hours in a jet.
Turbine time will always win over piston..
(well not entirely true as a C172 captain will get full credit for his hours towards and ATPL as opposed to an experienced FO, he will get 50% credit..)