If there are no traded options in a company you can get your broker to write OTC options but this may not be possible given some restrictions on accounts. Going short on futures may also be an option. You can also open a downside CFD (contract for difference) on the stock but will have to have margin posted against it so will have to hold cash (or possibly liquid assets if your AUM is large enough) to cover the margin which is unutilized cash in the portfolio that needs to be factored into any portfolio calculations as a cost. Diversifying into uncorrelated stock or shorting correlated (but low div yield) stock would also have the same effect.
stop loss orders would probably not be appropriate as it is not the price of the stock that you are concerned with but mitigating all price changes and just receiving the dividend on the stock.
warning: in a crash (almost) all stocks become suddenly correlated so be aware that might cause you a short term loss. CFDs are complex and require a degree of sophistication before you can trade them well but as you seem to understand options they should not be too hard to understand.