Well, from OFW 3.42 you have the ability to update to OFW 3.55 and continue onto a CFW 3.55 from there (Waninkoko, kmeaw, or geohot.) Each have their pros and cons, but all of them have a chance of bricking your console... some more than others *COUGH* Waninkoko *COUGH*. You also have the option of updating to OFW 3.56, but you've already stated that you have no desire to do so; smart move.
Did you purchase a pre-owned PS3? I'm curious because of the fact that you are currently on OFW 3.42. To the best of my knowledge, PS3s have been shipping with 3.40 for quite some time and only recently started shipping with 3.50. I only mention this because if your console shipped with 3.40, you can also downgrade from 3.42 to 3.41 with a jailbreak device and then use said jailbreak device like back in the good ol' days (Sept. '10?... man, where does the time go?) Downgrading a console that shipped with 3.50 is NOT recommended as it will more than likely brick your console. Once on OFW 3.41 you also have the option of updating to kakaroto's MFW 3.41. Hope this helps.