Most programs can easily be put on a second partition, but some are pretty stubborn about wanting themselves on C:

I think mine are 30gb for c and 205gb for D

Could even buy a second hard drive, like 10gb.... put the swap file on it for added speed

C: OS
D: Apps
E: Data

Second HD
F: Swap File

Or is that overkill?

With partitions its still on the same drive, so it may or may not be a little slower, may even be faster.
If a second HD, its faster I believe since you can read from two places at once.