GPS Tracking Collar Options

I've asked around at different places about what GPS tracking options for working dogs are out there. So far I haven't come up with any great options so I figured I'd ask in this corner of the internet (so far have looked at Garmin, Dogtra, some other cheap looking options). Can any of you guys give me some idea of what you're using or know works?

Here's the catch, it's got to be tracking only - no remote correction capability and it has to be strictly GPS - no cell system dependency - must not have bright orange or neon components, as most sport dog stuff is. Tough, professional grade product that's waterproof and has fair battery life is a must too. AO runs full gammut of urban to wilderness/remote, four season climate. Would like capability to utilize cell phone for monitoring but if an independent device is necessary that's fine too. Thanks in advance for any and all input.