not sure if i'd get maxtor, either. sure, they're ata133 but there are ata100 drives out there that actually perform a little better (ibm 120gxp and w.d. "JB"). the western digitals are the more expensive of the 3, though (80gb minimum). the maxtor and ibm's are about equally priced.
a raid controller is good to have simply cuz you're likely to have more than 4 ide devices at some point and will need the extra ports.
i was going to suggest a lower-end video card since you didn't mention gaming at all, but i looked at some screenshots of cinema 4d and i think the ti 4200 will do you good. im not a fan of ati, but some rave about their image quality and color accuracy, but i don't know if that's true anymore with gf3 and 4's.
the only difference between kt333 and kt266a boards is the memory controller... so your kt333 will actually be more of a kt266a if you use pc2100 memory. i know the 2 chipsets are almost the same price, though so it's okay. kt400 (using pc3200) will be out in not too long, just so you know.
and finally... nice case. }:>