An AGP Pro slot is simply an AGP4X slot with additional power pins to supply more power to the graphics card then the typical AGP implementation is cabale of. AGP Pro is generally only used for professional level video cards, such as those produced by 3DLabs, and FireGL cards.
The GF3 Ti200 does not require an AGPPro slot, though it is possible for a manufacturer to design an AGPPro based GF3 Ti200 I see little logical reason for it as the GF3 does not need any more power then a regular AGP4X slot can handle.