Isometric 3D tile game with Crystal Space? (Final Fantasy Tactics)

I'm thinking about using C4 to create a "3D tile" based game such as Final Fantasy Tactics or Disgaea.

Here are some screenshots of what I'm referring to:

Many more pictures can be found here: http://www.gamedev.net/community/forums/topic.asp?topic_id=391326

Another example:

...and more pictures can be found here: http://www.gamedev.net/community/forums/mod/journal/journal.asp?jn=403398&cmonth=3&cyear=2008

Anyways, how easy would this be to create?

These games seem to use "3D tiles" for the terrain with a grid-based system for movement.

Can anybody give me any advice or tips on creating this?

Thanks so much!