I've run a CDwriter on a Pentium 166mhz. But that was a 4x CDR. With the faster CDwriters, you will need Pentium II or faster to avoid buffer underrun errors when writing.
internal CD-writers usually comply with IDE specifications ... for cd-writing, ram requirement isn't critical and limited only by the OS ... the pc of wildthing should work just fine with an internal unit ... to avoid buffer underruns, don't run other programs when burning cd