Personally I would say that that would be ample, looks like an interesting project!

Well here is what I have done so far. (Everything was done to scale [in.]).
Edit: I just noticed that it's a bit backwards. Though it's not the final design, so i'll fix it later.
 

 

 
 

Just watch you cases air flow, static case air and case air volume. Or ya'll cause the wood too warp from the heat. Also, look at getting arcylic rad shrouds for between the wood and rad.

What do you guys think is the best type of wood for this? I was thinking of using kiln-dried pine since it's so cheap ($20 for a 1" x 12" x 12' board).

Oak & maple are also easily acquirable. $50-60 for a 1" x 8" x 8' plank though. 

Do you have a table saw? If so, you can cut your own trees, block them, dry them and board them yourself for nothing. I made a couple guitar bodies that way years ago just.to see if I could and they came out great. You can always put plexi panels up on the inside of the case to seperate your components from the wood. Or a few layers of laquer and a wax finish would also work well too. No matter what it's gonna be alot of work. Depending on how big you go with this case, you may want to look at some softer woods if weight is a consideration for you. Hard woods are nice and usually have the nicer grains but in something like this the weight can def add up. unless your going.to do a cheaper ply wood to build it and then get thin eighth inch ply wood panels of the precious woods to finish over tbe cheap plywood.

Ok, thanks guys gonna' get oak then.

I'll probably make the prototype out of pine since it's cheap.

Thanks for your invaluable help knightsilver. I do have a table saw and pretty much any other woodworking tool I'll ever need btw.
 

Looking Good. Just make sure the wood u get is not sap saturated like Pine or such since even after treatment they tend Bleed sap months later or years later or some been in storage could make sap more soluble with heat.

What's a sheet of 4x8 3/4 Oak ply cost up there?

Think about the cutouts for the radiators that you are going to use and not the round holes based on the fan size.
This way you will not block any part of the radiator air flow.
You could even put them flush with the wood and on top of your case place a fan $34.99 3x120mm Fan Radiator Shroud, Black or make one from the extra wood that you will have.