How long have you thought about the design of your game? Makeing a rpg will bring you into GREAT trouble:

Thousends of thousends classes which all relate with each other:
Inventory, Char Stats, Battle System (trust me makeing a little battle system alone is an nearly impossible difficult thing too do), Overword Map, Location Map, Grafix&FX, File I/O, Gamelenght, AI.

If you want to start gamedevelping then i recommend to do something much simpler e.g. trie to make a clone of the FF5 Battle System.

Wow, sounds like you are doing the exact same thing as me: writing an rpg with another person to do graphics etc. I started out writing the whole thing with directdraw, and made a 2d isometric graphics engine that worked fairly well.
When I saw Tan''s book I thought, wow, this is exactly what I''ve been doing. I bought it, read through much of it, and decided it was too easy. So I decided to skip to the last 2 chapters where he goes into 3d, fell in love with the idea, and started over with a 3d engine.
Now, about a week later, I am smacking myself for switching to 3d. I didn''t think it would be that much harder. I was wrong, at least I think so right now. Probably the learning curve is just quite steep.
I must say, however, that I find D3D8 much different from anything I''ve done in directdraw. It would therefore not be an easy matter to convert code from dd to d3d. It really depends what you are looking forward to most to code. If you want to write the graphics engine and see pretty pictures on the screen, you should program your engine in d3d. If you want to work more on the ai, inventory, scripting, story developing etc, use dd to jump over the graphics hurdle quickly.
I have found that there is a fine art to keeping your artist happy and thus working for you. If you make too many demands, they sort of give up and you don''t have an artist anymore, or at least not one that produces useable graphics. D3D is a lot easier on your artist because they can just make rectangular textures, rather than isometric tiles. D3D then takes care of the rest.
Alright, I''ll quit before I babble on any further. In the end, it is basically a matter of choice whether to use dd or d3d. Do what you think you can handle. If you have questions or such, you can reach me at jzeppenfeld@excite.com
Good luch, and have fun programming,.

If you want to use 2d in 3d, check out zero-one''s d3dx sprite library at http://www.angelfire.com/realm/zeroone/2dsprite.htm. I haven''t used it personally, but it looks like a really nice wrapper for the d3dx sprite function.

A wrapper is simply a set of functions that make it easier to work with something. The zero-one spritelib is a wrapper for the d3d sprite object. It really doesn''t add any functionality, it just makes it more user-friendly.
One thing about wrappers: They generally have some overhead associated with them. If you need your code to run faster, you should usually use the most low-level functions you can get your hands on.
Hope that helps.