This was a bit back in the thread, but hey, I am catching up.
Regarding pendants, you don't really need one, you can use the keyboard to jog (arrow keys, page up/down). If you want a cheap pendant, LinuxCNC (and I believe Mach) can use inexpensive USB game pads as pendants. I have not set one up yet, so I don't know the level of difficulty, but it's something to keep in mind.
DMS