CLIPPER/C App to ORACLE??, or C/C++ ???

Hi,

  We've got a realtime trading system writen in CLIPPER, with a few C routines, and two third party libraries. It's time to consider converting, question is to what? A Preliminary assesment suggests ORACLE, or C/C++.
I am requesting comments, suggestions, info, on this; also, we want to run these on PENTIUMS (top-of-the-line, fast, and many MEGS of RAM available). Anyone who has done this, or a similar conversion? What version, or type of ORACLE software? Seems to a novice like me that there are numerous versions and flavors of ORACLE! How to begin? What training courses? Many thanks.

Dave