HELP!!!!!

As some of oyu know, I am going to be getting a new GSP in the near future. He will be used primarily for upland, and when the opportunity comes, some duck too. Anyhow. I have been reading through the forums, and searching the companies that make / sell training collars. I just don't know much about any of them. I am looking to keep my $$ out to about $500 or less. What brand / model of training / beeper collar do you recommend and why. pros and cons of a few if you have owned different models. Any hole you can offer would be great.

Thanks in advance