This may be an ignorant question, but I wanted to know if I could use
m0n0wall with a frame relay circuit, and if so what equipment is
necessary?

To this point, I've mostly used DSL and cable modems with m0n0wall.  I
have a customer that is looking into getting a 2Mb frame relay
circuit, and wanted to know how I could integrate m0n0wall with it.

Is there a PCI card that I can put in the m0n0wall that will terminate
the frame relay?  Or will I need some sort of external hardware
similar to a DSL modem?

Thanks.