Use any payload with no spoof but with peek & poke sys calls (i.e any one compatible with mount alejandro or freeflash.) If you can't find one or don't know what this means you really shouldn't be installing this.
so, what's the difference from an ps3key firmware updare 4.0 (hermes payload 4b)and rebug hermes 4b?
without checking i'm going to guess the ps3key one has 3.50 spoof enabled, try it and see. If mount alejandro/free flash work then you're good to go, if not try another payload, rinse and repeat. it's not that complicated.