I just ordered by phone half a dozen items for a P-10 S OR.
Among the items I wanted was a firing pin and main spring - they said I could order them it would be about $45 USD or for about and additional $10 USD I could get the whole firing pin assembly. I went that way - It includes the two clips you mention - shipping is a flat $9 via Fed-EX.
I just mention it because it you intend to have some spare parts on hand buying the assembly might be over all cheaper.