Regarding the decent mic question:
I've been using a Nady mic that I think was $40... probably less... for years. It is perfect, in my opinion. It's also low impedance so I run it through a preamp before the PC. So the answer is: if it sounds good then why get better? And with audio editing programs you can usually remove white noise so unless it is horrible, I'd use it.
As for your next question:
DarkVOICES is a program that you use to lip-sync 3D models to audio.
Adobe Soundbooth is just audio editing.
Then for if you need anything special:
Well, I'm not sure I'd use DarkBASIC for 3D animation. If you want it to be interactive, then I'd use DBPro, but I think you'd be much better served by learning Blender for this. Besides that, it takes a good machine to render high def 3D scenes in a reasonable amount of time. I've got an AMD Phenom X6 1090T and dual Radeon HD5830s and it takes about 2-5 seconds per frame of 1900x1080 with not a lot of shadows. At 24fps it can add up quite quickly.
Give me a buzz if you need more info. I've got a ton of resources on Blender if your interested in learning.
