Steve, thanks for the connection help in advance. I'm still waiting on the GTD 787 wireless mic and Nady mic mixer to arrive. When I get them I will know what to look out for when testing it out--like dunlopj said in his post.
Drzinc, I went with the Nady because I have 2U rack space in my rack (one for the wireless mic system, the other mic mixer), cost had a factor, and I needed something simple that works for me--time will tell. Behringer would have taken too much rack space and it had more stuff than what I needed at this time--still it's a very good product. I just needed something simple so I could control the individual volume for the four mic I'll be getting.
If the Nady causes too many issues/problems for myself, I will forget trying to control the individual mic and get rid of the Nady mic mixer and just use my current mixer to control all 4 mic at once. If I desperately need to control the mic individually; drzinc I will take your route.