Ok new in here so be gentle:

I'm a programmer with the need to also be a sys admin on a box running:
Client has purchased a Kyocera KM-4035 do it all machine. However, no driver exists for SCO and when I contacted their Kyocera rep he told me to install CUPS. I downloaded CUPS and ran ./configure which displays the following
I googled some things and it looks like C needs to be on the box.
Now I am at a loss on how to prodeed.

Can anyone provide advice?

Most of printers understand PCL (=HP) drivers, have you tested ? Kyocera also support PCL.

Kyocera support raw printing (port 9100) and I'm sure that it support also lpd (port 513). Manual usually include queue name for lpd printing.

CC-compiler:
Go to SCO pages, look Skunkware, there you can find ex. gcc packet to install.

Yes you do need a C compiler to proceed with the installation of CUPS you have downloaded, as the CUPS website suggests have you tried searching for CUPS binaries for SCO otherwise you will need to locate gcc for SCO Unix?

Unix printing is usually postscript but there are conversion binaries around which is presumably what CUPS will do for you.
If you want to try not using cups you could try the ps2pcl tools mentioned here: Linut's SCO stuff.(ghostpcl section) and do something like: