So you have a decent mic and a board. Now you need some dynamics reduction to make it sound great before you run it into your sound card.
Used improperly, compression can ruin the sound of your program. Used properly, dynamics compression can make your program sound much more consistent and professional.
Two of my favorites: The Aphex Compellor 320a ($1075) and the RNC 1773 ($170). First the Compellor:
The Aphex Compellor 320A is a two channel compressor/limiter.
This is the preferred piece of hardware for great sounding audio and it’s really difficult to screw it up! Three controls for each channel, an input, a process knob, and an output. With this box, it’s next to impossible to make your audio sound bad. And it does it’s job remarkably well. Inputs and outputs are balanced XLR. They have a new model with digital inputs and outputs…you don’t need it in most cases. Check ebay, I've bought them for $300 recently.