Looks to me like you want a topographic map of Mars. (Generated by the kewl MOLA project)
They talk about liquid water, and it looks like they even take into account the new water-containing South pole theory.
Personally, I’d take a look at this amazing, clickable Astronomy Picture of the Day and explore the sites related to it. (They’re listed underneath it) For the sake of reality, perhaps check into where they pulled their 0m mark from.
The logistics of current terraforming plans kinda depended on that CO2 for the greenhouse effect, but assuming you can get by that, it appears the “Hellas impact basin” would become the focus of a huge new beach-front real estate industry, and that ocean shipping would be restricted to the northern hemisphere.