There are Vcarve plugins available for CamBam, but it's something I've never tried. Searching for "vcarve" over on the CamBam forums will through up a few threads with various links.

I've looked at Estlcam previously, particularly it's Trochoidal feature. In general I found it a bit simplistic, which limited what you could do with/configure it, however it must be a couple years since I last tried it.
I can't remember exactly why it wouldn't work for me, but I went back to CamBam. I think it was because you had to manually compensate for the cutter width when doing Troichoidal, and Troichoidal was only available for slots, not clearing complete profile sections.

I will say though, Estlcam is good package, and is probably worth buying even if you only use it for certain jobs.